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Zero Property: For any number ‘a’, a × 0 = 0 × a = 0. For example, 601 × 0 = 0 × 601 = 0. Commutative Property: If ‘a’ and ‘b’ are any two numbers, then a × b = b × a. For example, 25 × 7 = 175 = 7 × 25. Associative Property: If ‘a’, ‘b’ and ‘c’ are any three numbers, then a × (b × c) = (a × b) × c. For example, 3 × (4 × 5) = (3 × 4) × 5 3 × 20 = 12 × 5 60 = 60 Let us answer the following to revise the the multiplication of 4-digit numbers. a) Th H T O b) Th H T O c) Th H T O 3234 1274 4567 ×2 ×8 ×5 d) Th H T O e) Th H T O f) Th H T O 5674 3120 4372 ×3 ×4 ×8 & Remembering and Understanding Multiplication of large numbers is the same as multiplication of 4-digit or 5-digit numbers by 1-digit numbers. If an ‘x’-digit number is multiplied by a ‘y’-digit number, then their product is not more than a ‘(x + y)’- digit number. Let us solve some examples of multiplication of large numbers. Multiplication 52 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 101 1/7/2019 3:09:33 PM

Example 1: Find these products. a) 2519 × 34 b) 4625 × 17 Solution: a) T Th Th H T O b) T Th Th H T O 12 23 413 2519 4625 ×34 ×17 11 1 0 0 7 6 → 2519 × 4 ones 3 2 3 7 5 → 4625 × 7ones + 7 5 5 7 0 → 2519 × 3 tens +4 6 2 5 0 → 4625 × 1 tens 8 5 6 4 6 → 2519 × 34 7 8 6 2 5 → 4625 × 17 Example 2: Find the product of 3768 and 407. Solution: T L L T Th Th H T O Here we can skip 323 the step ‘3768 × 0’ but, add one more zero in 545 3768 tens place while ×407 multiplying by 1 hundreds digit. 2 6 3 7 6 → 3768 × 7 ones + 1 5 0 7 2 0 0 → 3768 × 4 hundreds 1 5 3 3 5 7 6 → 3768 × 407 Example 3: Estimate the number of digits in the product of 58265 and 73. Then multiply and verify your answer. Solution: The number of digits in the multiplicand 58265 is five. The number of digits in the multiplier 73 is two. Total number of digits is seven. Therefore, the product of 58265 and 73 should not have more than seven digits. 53 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 102 1/7/2019 3:09:33 PM

T L L T Th Th H T O 5 143 Example 4: 2 11 Solution: 5 8265 ×73 11 11 1 7 4 7 9 5 → 58265 × 3 ones + 4 0 7 8 5 5 0 → 58265 × 7 Tens 4 2 5 3 3 4 5 → 58265 × 73 The number of digits in the product 4253345 is 7. Hence, verified. Find the product of 24367 and 506. T L L T Th Th H T O 2 133 2 244 2 4367 ×506 1 1 4 6 2 0 2 → 24367 × 6 ones + 1 2 1 8 3 5 0 0 → 24367 × 5 hundreds 1 2 3 2 9 7 0 2 → 24367 × 506 Application We use multiplication of numbers in many real-life situations. Let us see a few examples. Multiplication 54 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 103 1/7/2019 3:09:33 PM

Example 5: A farmer has 6350 acres of mango farm. If he L T Th Th H T O needs 58 kg of fertiliser for each acre, how 12 Solution: many kilograms of fertiliser does he need in all? Quantity of fertiliser required for 1 acre of farm 24 Example 6: Solution: = 58 kg 6350 Quantity of fertiliser required for 6350 acres ×58 of farm = 6350 × 58 kg 1 Example 7: Solution: = 368300 kg 5 0800 +3 1 7 5 0 0 3 6 8300 The cost of one fridge is ` 9528. What is the cost of 367 such fridges? Cost of one fridge = ` 9528 Cost of 367 fridges = ` 9528 × 367 T L L T Th Th H T O 12 314 315 9528 ×367 1 1 1 11 6 6696 + 5 7 1680 + 2 8 5 8400 3 4 9 6776 Therefore, the cost of 367 fridges is ` 3496776. A clothier sells different suiting and shirting and earns ` 48657 per day. How much does he earn in one week? L T Th Th H TO 6 43 4 Amount earned by a clothier in one day = ` 48657 4 86 57 ×7 Amount earned by him in one week 3 4 05 99 (7 days) = ` 48657 × 7 Therefore, amount earned by the clothier in a week is ` 340599. 55 1/7/2019 3:09:33 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 104

Higher Order Thinking Skills (H.O.T.S.) Let us see a few more real-life examples involving multiplication of large numbers. Example 8: A cloth mill produces 8573 m of cloth in a day. How many metres of cloth can it produce in January, if there are six holidays in the month? Solution: Length of the cloth produced by a cloth mill in a day = 8573 m In January, if six days are holidays, the number of working days = 31 – 6 = 25 Length of cloth produced in 25 days = 8573 m × 25 = 214325 m Example 9: Find the missing numbers in the given product. T Th Th H T O 3417 ×63 1 21 + 0 5 20 21 271 Solution: T Th Th H T O 3417 ×63 1 0251 +2 0 5 0 2 0 2 1 5271 Example 10: Observe the pattern and write the next two terms. 4×4=16 34 × 34=1156 334×334=111556 ---------------------------------- ---------------------------------- Multiplication 56 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 105 1/7/2019 3:09:33 PM

Solution: The next two terms in the given pattern are 3334×3334=11115556 33334×33334=1111155556 Drill Time Concept 5.1: Multiply Large Numbers 1) Solve: a) 12345 × 7 b) 90962 × 113 c) 3578 × 575 d) 8869 × 450 e) 5124 × 52 2) Word problems a) A cloth factory produces 32674 m of cloth in a week. How many metres of cloth can the factory produce in 6 weeks? b) A table costs ` 1354. Find the cost of 73 such tables. c) Find the product of the largest 4-digit number and the largest 2-digit number. d) There are 5606 bags of rice in a storehouse. If each bag weighs 62 kg, what is the total weight of the bags of rice? 57 1/7/2019 3:09:33 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 106

Chapter Division 6 Let Us Learn About • dividing 5-digit by 1-digit and 2-digit numbers. • rules of divisibility • finding prime and composite numbers. • factors, multiples, H.C.F. and L.C.M. of numbers. • prime factorisation of numbers. Concept 6.1: Divide Large Numbers Think Pooja’s brother saved ` 12500 in two years. He saved an equal amount every month. Pooja wanted to find his savings per month. How do you think Pooja can find that? Recall In Class 4, we have learnt dividing a 4-digit number by a 1-digit number. Let us now revise this concept with a few example. Divide: a) 3165 ÷ 3 b) 5438 ÷ 6 c) 2947 ÷ 7 d) 7288 ÷ 4 e) 1085 ÷ 5 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 107 58 1/7/2019 3:09:33 PM

& Remembering and Understanding Dividing a 5-digit number by a 1-digit number is the same as dividing a 4-digit number by a 1-digit number. Example 1: Divide: a) 12465 ÷ 5 b) 76528 ÷ 4 Solution: a) 2493 b) 19132 )5 12465 )4 76528 −10 −4 24 36 − 20 − 36 46 05 − 45 − 04 15 12 − 15 − 12 0 08 −8 0 Let us now divide a 5-digit number by a 2-digit numbers. Example 2: Divide: 21809 ÷ 14 Solution: Write the dividend and the divisor as Divisor Dividend Steps Solved Solve these 14 21809 Step 1: Guess the quotient by )20 53174 dividing the two leftmost digits by 14 × 1 = 14 the divisor. Find the multiplication fact which 14 × 2 = 28 has the dividend and the divisor. 14 < 21 < 28 So,14 is the number to be subtracted from 21. 59 1/7/2019 3:09:33 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 108

Steps Solved Solve these Step 2: Write the factor other than Write 1 in the quotient and )13 34567 the dividend and the divisor as 14 below 21, and subtract. the quotient. Then bring down the next number in the dividend. 1 14 21809 −14 78 Step 3: Repeat steps 1 and 2 until 1557 )15 45675 all the digits of the dividend are brought down. )14 21809 Stop the division when the − 14 remainder < divisor. 78 − 70 80 − 70 109 − 98 11 Step 4: Write the quotient and the Quotient = 1557 remainder. The remainder must Remainder = 11 always be less than the divisor. Checking for the correctness of division: We can check if our division is correct using a multiplication fact of the division. Step 1: Compare the remainder and the divisor. Step 2: Check if (Quotient × Divisor) + Remainder = Dividend Division 60 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 109 1/7/2019 3:09:33 PM

Let us now check if our division in example 2 is correct or not. Step 1: Remainder < Divisor Dividend = 21809 Divisor = 14 Step 2: (Quotient × Divisor) + Quotient = 1557 Remainder = Dividend Remainder = 11 11 < 14 (True) 1557 × 14 + 11 = 21809 21798 + 11 = 21809 21809 = 21809 (True) Note: 1) If remainder > divisor, the division is incorrect. 2) If (Quotient × Divisor) + Remainder is not equal to Dividend, the division is incorrect. Application Let us now see a few real-life examples of division of large numbers. Example 3: A machine produces 48660 pens in the month of June. How many pens does it Solution: produce in a day? 1622 Number of days in the month of June = 30 )30 48660 Number of pens produced in the month = 48660 − 30 Number of pens produced in a day = 48660 ÷ 30 186 − 180 66 − 60 60 − 60 Therefore, the machine produces 1622 pens in a day. 00 61 1/7/2019 3:09:33 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 110

Example 4: Vijay bought 15375 sheets of paper for 35 students of his class. If the sheets are Solution: distributed equally, how many sheets would each student get? Will any sheets remain? = 15375 439 Total number of sheets )35 15375 Number of students = 35 -140 137 Number of sheets each student gets = 15375 ÷ 35 - 105 Therefore, the number of sheets each student gets = 439 325 Number of sheets that remain = 10 - 315 Rules of divisibility 10 Divisibility rules help us to find the numbers that divide a given number exactly. By using them, we can find the factors of a number, without actually dividing it. Divisor Rule Examples 2 The ones digit of the given number must be 0, 2, 4, 6 10, 42, 56, 48, 24 3 or 8. 4 The sum of the digits of the given number must be 36 (3 + 6 = 9) divisible by 3. 48 (4 + 8 = 12) 5 1400, 3364, 2500, 7204 The number formed by the last two digits of the given number must be divisible by 4 or both the digits 230, 375, 100, 25 must be zero. The ones digit of the given number must be 0 or 5. 6 The number must be divisible by both 2 and 3. 36, 480, 1200 9 The sum of the digits of the given number must be 36 (3 + 6 = 9) divisible by 9. 144 (1 + 4 + 4 = 9) 10 The ones digit of the given number must be 0. 300, 250, 5670 Let us now apply the divisibility rules to check if a given number is divisible by 2, 3, 4, 5, 6, 9 or 10. Example 5: Which of the numbers 2, 3, 4, 5, 6, 9 and 10 divide 42670? Solution: To check if 2, 3, 4, 5, 6, 9 or 10 divide 42670, apply their divisibility rules. Divisibility by 2: The ones place of 42670 has 0. So, it is divisible by 2. Divisibility by 3: The sum of the digits of 42670 is 4 + 2 + 6 + 7 + 0 =19. 19 is not divisible by 3. So, 42670 is not divisible by 3. Division 62 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 111 1/7/2019 3:09:33 PM

Divisibility by 4: The number formed by the digits in the last two places of 42670 is 70, which is not exactly divisible by 4. So, 42670 is not divisible by 4. Divisibility by 5: The ones place of 42670 has 0. So, it is divisible by 5. Divisibility by 6: 42670 is divisible by 2 but not by 3. So, it is not divisible by 6. Divisibility by 9: The sum of the digits of 42670 is 4 + 2 + 6 + 7 + 0 = 19, which is not divisible by 9. So, 42670 is not divisible by 9. Divisibility by 10: The ones place of 42670 has 0. So, it is divisible by 10. Hence, the numbers that divide 42670 are 2, 5, and 10. Example 6: Complete this table. Number Divisible by 2 3 4 5 6 9 10 464 390 3080 4500 Solution: Apply the divisibility rules to check if the given numbers are divisible by the given factors. Number 2 3 Divisible by 9 10 456 464        390        3080        4500        Higher Order Thinking Skills (H.O.T.S.) Let us see a few examples where we use the of divisibility rules in some real-life situations. Example 7: In a nursery, there are 4056 plants. How many can be planted in each row, if there are 2, 3, 4, 5, 6, 9 or 10 rows? Will some plants be left over in any of the arrangements? Solution: Number of plants in the nursery = 4056 4056 is divisible exactly by: 63 1/7/2019 3:09:33 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 112

2 (since the ones digit is 6), 3 (since 4 + 0 + 5 + 6 = 15), 4 (since 56 is divisible by 4) and 6 (since 4056 is divisible by 2 and 3). So, we can arrange 4056 plants in rows of 2, 3, 4 or 6. Since 4056 is not exactly divisible by 5, 9 and 10, some plants remain if they are arranged in 5, 9 or 10 rows. Example 8: Dilip shares 350 stamps with his friends. If he gives 2, 3, 5 or 10 stamps to each friend, will all the stamps be shared? Solution: Number of stamps Dilip shares = 350 If Dilip shares 2, 5 or 10 stamps each, all the stamps will be distributed as 2, 5 and 10 divide 350 exactly. If he gives 3 stamps to each of his friends, some stamps remain as 350 is not exactly divisible by 3. Concept 6.2: Factors and Multiples Think Pooja learnt to find factors of a given number using multiplication and division. She wants to know the name given to the product obtained when we multiply numbers by counting. Do you know the name given to such products? Recall The numbers that divide a given number exactly are called the factors of that number. In other words, the numbers, which when multiplied ,give a product are called the factors of the product. For example, in 12 × 9 = 108, the numbers 12 and 9 are called the factors of 108. The number 108 is called the product of 12 and 9. Division 64 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 113 1/7/2019 3:09:33 PM

Complete the multiplication table of 8. 8×1=8 8×2= 8×3= 8×4= 8 × 5 = 40 8 × 6 = 48 8×7= 8 × 8 = 64 8×9= 8 × 10 = & Remembering and Understanding The products obtained when a number is multiplied by 1, 2, 3, 4, 5 …. are called the multiples of that number. In a multiplication table, a number is multiplied by the numbers 1, 2, 3, 4, 5 and so on till 10. In the multiplication table of 8, the products obtained are 8, 16, 24, 32, 40 and so on till 80. These are called the first ten multiples of 8. Similarly, a) 2, 4, 6, 8, 10, 12 … are the multiples of 2. b) 5, 10, 15, 20, 25, 30… are the multiples of 5. Let us now find the factors of some numbers. Factors of numbers from 1 to 10: Number Factors Number of Number Factors Number of factors factors 1 1 1 6 1, 2, 3, 6 4 2 1, 2 2 7 1, 7 2 3 1, 3 2 8 4 4 1, 2, 4 3 9 1, 2, 4, 8 3 5 1, 5 2 10 1, 3, 9 4 1, 2, 5, 10 From the given table, we observe that: 1) The number 1 has only one factor. 2) The numbers 2, 3, 5 and 7 have only two factors (1 and themselves) 3) The numbers 4, 6, 8, 9 and 10 have three or four factors (more than two factors). Note: 1) The numbers that have only two factors (1 and themselves) are called prime numbers 2) The numbers that have more than two factors are called composite numbers. 3) The number 1 has only one factor. So, it is neither prime nor composite. 65 1/7/2019 3:09:33 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 114

Sieve of Eratosthenes Eratosthenes was a Greek mathematician. He created the sieve of Eratosthenes, to find prime numbers between any two given numbers. Steps to find prime numbers between 1 and 100 using the sieve of Eratosthenes: Step 1: Prepare a grid of numbers from 1 to 100. Step 2: Cross out 1 as it is neither prime nor composite. Step 3: Circle 2 as it is the first prime number. Then cross out all the multiples of 2. Step 4: Circle 3 as it is the next prime number. Then cross out all the multiples of 3. Step 5: Circle 5 as it is the next prime number. Then cross out all the multiples of 5. Step 6: C ircle 7 as it is the next prime number. Then cross out all the multiples of 7. Continue this process till all the numbers between 1 and 100 are either circled or crossed out. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 The circled numbers are the prime numbers and the crossed out numbers are the composite numbers. Division 66 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 115 1/7/2019 3:09:33 PM

There are 25 prime numbers between 1 and 100. These are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89 and 97. Note: 1) All prime numbers (except 2) are odd. 2) 2 is the only even prime number. Example 9: Find the factors: a) 16 b) 40 Solution: a) T o find the factors of a given number, express it as a product of two numbers as shown: 16 = 1 × 16 =2×8 =4×4 Then write each factor only once. So, the factors of 16 are 1, 2, 4, 8 and 16. b) 40 = 1 × 40 = 2 × 20 = 4 × 10 =5×8 So, the factors of 40 are 1, 2, 4, 5, 8, 10, 20 and 40. Example 10: Find the common factors of 10 and 15. Solution: 10 = 1 × 10 and 10 = 2 × 5 So, the factors of 10 are 1, 2, 5 and 10. 15 = 1 × 15 and 15 = 3 × 5 So, the factors of 15 are 1, 3, 5 and 15. Therefore, the common factors of 10 and 15 are 1 and 5. We can find the factors of a number by multiplication or by division. Example 11: Find the factors of 30. Solution: Factors of 30 Using multiplication 1 × 30 = 30 2 × 15 = 30 3 × 10 = 30 67 1/7/2019 3:09:33 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 116

5 × 6 = 30 The numbers multiplied to obtain the given number as the product are called its factors. So, the factors of 30 are 1, 2, 3, 5, 6, 10, 15 and 30. Using division 30 ÷ 1 = 30 30 ÷ 2 = 15 30 ÷ 3 = 10 30 ÷ 5 = 6 The different quotients and divisors of the given number are its factors. So, the factors of 30 are 1, 2, 3, 5, 6, 10, 15 and 30. Facts on Factors 1) 1 is the smallest factor of a number. 2) 1 is a factor of every number. 3) A number is the greatest factor of itself. 4) Every number is a factor of itself. 5) The factor of a number is less than or equal to the number itself. 6) Every number (other than 1) has at least two factors – 1 and the number itself. 7) The number of factors of a number is limited. Let us now find the multiples of some numbers. Example 12: Find the first six multiples: a) 9 b) 15 c) 20 Solution: The first six multiples of a number are the products when the number is multiplied by 1, 2, 3, 4, 5 and 6. a) 1 × 9 = 9, 2 × 9 = 18, 3 × 9 = 27, 4 × 9 = 36, 5 × 9 = 45, 6 × 9 = 54. So, the first six multiples of 9 are 9, 18, 27, 36, 45 and 54. Now, complete these: b) 1 × 15 = 15, ___ × ___ = ____ , ___ × ___ = ___ , ___ × ____ = ____, ____ × ___ = ____, _____ × _____ = ____. So, the first six multiples of 15 are ____ , ____ , ____ , ____ , ____ and ____. Division 68 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 117 1/7/2019 3:09:33 PM

c) 1 × 20 = 20, ___ × ___ = ____, ___ × ___ = ___ , ___ × ____ = ____, ____ × ___ = ____ , _____ × _____ = ____. So, the first six multiples of 20 are ____, ____ , ____ , ____ , ____ and ____. Example 13: Find three common multiples of 10 and 15. Solution: Multiples of 10 are 10, 20, 30, 40, 50, 60, 70, 80, 90,100,…. Multiples of 15 are 15, 30, 45, 60, 75, 90, 105,…. Therefore, the first three common multiples of 10 and 15 are 30, 60 and 90. Facts on Multiples 1) Every number is a multiple of itself. 2) Every number is a multiple of 1. 3) A number is the smallest multiple of itself. 4) The multiples of a number are greater than or equal to the number itself. 5) The number of multiples of a given number is unlimited. 6) The largest multiple of a number cannot be determined. Application Finding factors and multiples helps us to find the Highest Common Factor (H.C.F.) and the Least Common Multiple (L.C.M.) of the given numbers. Highest Common Factor (H.C.F.): The highest common factor of two or more numbers is the greatest number that divides the numbers exactly (without leaving a remainder). Least Common Multiple (L.C.M.): The least common multiple of two or more numbers is the smallest number that can be divided by the numbers exactly (without leaving a remainder). Example 14: Find the highest common factor of 12 and 18. Solution: 12 = 1 × 12, 12 = 2 × 6 and 12 = 3 × 4 So, the factors of 12 are 1, 2, 3, 4, 6 and 12. 18 = 1 × 18, 18 = 2 × 9 and 18 = 3 × 6 So, the factors of 18 are 1, 2, 3, 6, 9 and 18. The common factors of 12 and 18 are 1, 2, 3 and 6. Therefore, the highest common factor of 12 and 18 is 6. 69 1/7/2019 3:09:33 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 118

Example 15: Find the least common multiple of 12 and 18. Solution: The multiples of 12 are 12, 24, 36, 48, 60, 72… The multiples of 18 are 18, 36, 54, 72… The common multiples of 12 and 18 are 36, 72… Therefore, the least common multiple of 12 and 18 is 36. Higher Order Thinking Skills (H.O.T.S.) Let us now complete these tables of H.C.F. and L.C.M. of the given numbers. Example 16: Complete the H.C.F. table given. Some H.C.F. values are given for you. Numbers 10 12 18 30 2 2 3 6 12 15 15 Solution: Numbers 10 12 18 30 2 2222 3 12 1333 15 2 12 6 6 5 3 3 15 Example 17: Complete the L.C.M. table given. Some L.C.M. values are given for you. Numbers 10 12 18 30 2 18 3 12 12 15 30 Solution: Numbers 10 12 18 30 2 10 12 18 30 3 30 12 18 30 12 60 12 36 60 15 30 60 90 30 Division 70 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 119 1/7/2019 3:09:33 PM

Example 18: How many prime and composite numbers are there between 35 and 55? Solution: The prime numbers between 35 and 55 are 37, 41, 43, 47 and 53 which are five in number. There are 19 numbers between 35 and 55, of which five are prime. So, 19 – 5 = 14 numbers are composite. Concept 6.3: H.C.F. and L.C.M. Think Pooja now knows prime and composite numbers. She wants to know a simple way to find H.C.F. and L.C.M. of two numbers. Do you know any simple method for the same? Recall We have learnt about prime and composite numbers and the definitions of H.C.F. and L.C.M. We first find the factors of the given numbers. The highest common number among them gives the H.C.F. of the given numbers. Likewise, we can find the multiples of the given numbers. The least common among them gives the L.C.M. of the given numbers. Let us revise the concept by finding the common factors of the following pairs of numbers. a) 12, 9 b) 15, 10 c) 30, 12 d) 24, 16 e) 35, 21 f) 36, 54 & Remembering and Understanding Prime numbers have only 1 and themselves as their factors. Composite numbers have more than two factors. So, composite numbers can be expressed as the products of their prime numbers or composite numbers. 71 1/7/2019 3:09:33 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 120

For example, 5 = 1 × 5; 20 = 1× 20 9 = 1 × 9, = 2 × 10 = 3 × 3; =4×5 We can express all composite numbers as the products of prime factors. Expressing a number as a product of prime numbers is called prime factorisation. To prime factorise a number, we use factor trees. Let us see a few examples to understand this better. Example 19: Prime factorise 36. Solution: To carry out the prime factorisation of 36, draw a factor tree as shown. Step 1: Express the given number as a product of two factors. One of these factors is the least number (other than 1) that can divide it. The second factor may be prime or composite. Step 2: If the second factor is a composite number, express it as a product of two factors. One of these factors is the least number (other than 1) that can divide it. The second factor may be prime or composite. Step 3: Repeat the process till the factors 36 cannot be split further. In other words, repeat the process till the factors do 2 × 18 × 9 not have any common factor other than 1. 2 × 2 Step 4: Then write the given number as the 2 × 2 × 3 × 3 product of all the prime numbers. Therefore, the prime factorisation of 36 is 2 × 2 × 3 × 3. Note: A factor tree must be drawn using a prime number as one of the factors of the number at each step. Division 72 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 121 1/7/2019 3:09:33 PM

Example 20: Prime factorise 54. Solution: Prime factorisation of 54 using a factor tree: 54 2 × 27 2 × 3 × 9 2 × 3 × 3 × 3 Therefore, the prime factorisation of 54 is 2 × 3 × 3 × 3. Application Finding H.C.F. using prime factorisation Let us now find the H.C.F. of two numbers using prime factorisation. Example 21: Find the H.C.F. of 48 and 54 by the prime factorisation method. Solution: The prime factorisation of 48 is 2 × 2 × 2 × 2 × 3. The prime factorisation of 54 is 2 × 3 × 3 × 3. Therefore, the H. C. F of 48 and 54 is 2 × 3 which is 6. Finding L.C.M. using prime factorisation Let us now find the L.C.M. of two numbers using prime factorisation. Example 22: Find the L.C.M. of 18 and 24 by prime factorisation method. Solution: Prime factorisation of 18 is 2 × 3 × 3. Prime factorisation of 24 is 2 × 2 × 2 × 3. Therefore, the L.C.M. of 18 and 24 is 2 × 3 × 2 × 2 × 3 = 72. Higher Order Thinking Skills (H.O.T.S.) Let us now solve a few examples involving the H.C.F. and L.C.M. of three numbers. First, express the numbers as products of prime factors, and then find their H.C.F. 73 1/7/2019 3:09:34 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 122

Example 23: Find the H.C.F. of 14, 28 and 35. Solution: Prime factorisation of 14 is 2 × 7. Prime factorisation of 28 is 2 × 2 × 7. Prime factorisation of 35 is 5 × 7. Therefore, the H.C.F. of 14, 28 and 35 is 7. Example 24: Find the L.C.M. of 14, 28 and 35. Solution: Prime factorisation of 14 is 2 × 7. Prime factorisation of 28 is 2 × 2 × 7. Prime factorisation of 35 is 5 × 7. Drill TThiemreefore, the L.C.M. of 14, 28 and 35 is 2 × 2 × 7 × 5 = 140. Concept 6.1: Divide Large Numbers 1) Divide: a) 43243 by 23 b) 50689 by 14 c) 52043 by 18 d) 21861 by 5 e) 72568 by 4 2) Word problems a) Which of the numbers among 2, 3, 4, 5, 6, 9 and 10 divide 893205? b) Which of the numbers among 2, 3, 4, 5, 6, 9 and 10 divide 24688? Concept 6.2: Factors and Multiples 3) Find the factors of the following: a) 36 b) 49 c) 100 d) 120 e) 91 4) Find the multiples of the following as given in the brackets: a) 7 (First 8) b) 15 (First 5) c) 100 (First 10) d) 25 (First 4) e) 30 (First 6) 5) Find the highest common factor of the following pairs of numbers. a) 12, 20 b) 15, 27 c) 24, 48 d) 16, 64 e) 30, 45 6) Find the least common multiple of the following pairs of numbers. a) 8, 10 b) 12, 15 c) 16, 20 d) 22, 33 e) 15, 30 Division 74 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 123 1/7/2019 3:09:34 PM

Concept 6.3: H.C.F. and L.C.M. 7) Prime factorise the following using the factor tree method. a) 108 b) 128 c) 56 d) 48 e) 63 8) Solve: a) Find the L.C.M. of 32 and 56 by prime factorisation. b) Find the H.C.F. of 25 and 75 by prime factorisation. c) Find the H.C.F. of 96 and 108 by prime factorisation. d) Find the L.C.M. of 45 and 75 by prime factorisation. 75 1/7/2019 3:09:34 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 124

EVS−I (Science) Textbook Features Let Us Learn About Think Contains the list of learning objectives to Introduces the concept/subtopic and be achieved in the lesson arouses curiosity among students Understanding Remembering Explains the aspects in detail that form Introduces new concepts to build on the basis of the concept the prerequisite knowledge/skills required Includes elements to ensure that students to understand and apply the objective are engaged throughout of the topic Application Amazing Facts Connects the concept to real-life Fascinating facts and trivia related to situations by enabling students to apply the concept what has been learnt through the practice questions Higher Order Thinking Skills (H.O.T.S.) Encourages students to extend the concept learnt to advanced application scenarios Inside the Lab Provides for hands-on experience with creating, designing and implementing something innovative and useful NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 125 1/7/2019 3:09:34 PM

EVS−I (Science) Contents 5Class 1 Muscular System������������������������������������������������������������������������������������������������1 2 Respiratory System���������������������������������������������������������������������������������������������6 3 Nervous System�����������������������������������������������������������������������������������������������10 4 Floats, Sinks and Mixes������������������������������������������������������������������������������������ 14 Inside the Lab – A��������������������������������������������������������������������������������������������������19 Activity A1: Respiratory System Activity A2: Water as a Universal Solvent 5 Fruits and Seeds������������������������������������������������������������������������������������������������21 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 126 1/7/2019 3:09:34 PM

Lesson Muscular System 1 Let Us Learn About R muscles and the muscular system. u the functions of our muscles. a keeping our muscles healthy. h injuries related to muscles. Think While playing kabaddi with friends, Raghav injured his hand. His mother took him to a doctor. After checking his hand, the doctor said that it was a muscle injury and not a fracture. Raghav wondered what a muscle is and how it looked. Do you know about muscles? Remembering Make a fist and fold your hand at the elbow. the human Touch your upper arm with your other hand. muscular Can you feel a soft and spongy material inside? system Now, while still touching it with your fingers, slowly unfold the arm. Can you feel some movement inside the upper arm? These are muscles. Muscles are present all over our body. All the muscles together form an organ system called the muscular system. NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 127 1 1/7/2019 3:09:34 PM

According to the place where muscles are, they can be of three different types. They are: Skeletal muscles: These are muscles which are attached to 1 the bones. They pull the bones to make movements of hands and legs. We can control these muscles. Smooth muscles: These are muscles on the walls of internal 2 organs. For example, the muscles of the stomach, intestines and so on. They are not attached to the bones. Heart (Cardiac) muscles: These 3 muscles are found only in the heart. Both the smooth and the heart muscles are not controlled by us. They work throughout the day on their own with the help of our brain. Understanding Why do we have muscles in our body? The main function of the muscular system is the movement of different body parts. Try this: muscles becoming loose and tight Make a fist. Tighten the fist. Then loosen the fist. What do you feel? We can feel the muscles moving. They help in movement by becoming tight and loose like a spring or a rubber band. For example, to bend our hand, some muscles will become tight and some will become loose. 2 1/7/2019 3:09:34 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 128

Let us see some movements using muscles. muscles help Heart muscles in movement help the heart to The muscles attached to the pump blood. bones help in movements of hands, legs and so on. Example: walking, running, writing and so on Muscles around the lungs (the rib Did you know that your lips and cage muscles and a dome-shaped lips and tongue are made tongue are muscle at the base of the chest up of muscles too? These made of cavity) help in breathing. When muscles help us while muscles these muscles contract and relax, talking and eating. air flows in and out of the lungs. muscles help Muscles help us to maintain body posture. to breathe They help to keep us upright and erect. Smooth muscles Muscles also provide heat to our body. When we feel of the stomach cold, our muscles vibrate muscles rapidly to generate body vibrate in and intestines help heat. This is the reason cold weather why we shiver when we in the movement feel cold. and digestion of food. muscles help in digestion Application Muscles are an important part of our body, so they should be healthy. Healthy food and regular exercise make the muscles stronger and healthier. We should follow these practices to keep our muscles healthy and strong: 1) Warm up → exercise → cool down: Exercise for 15–20 minutes every day. Warm up the different body parts with a brisk walk or a light jog before starting with exercise. After the exercise, let the body cool down slowly. Doing warm up before exercise prepares the body for the exercise. This is because the heart pumps more blood to the muscles. So, the brisk walk light jog chance of injury due to exercising is reduced. Muscular System 3 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 129 1/7/2019 3:09:34 PM

2) Stretch: Stretch all body parts every day. It improves stretching all parts of body the strength of muscles. 3) Drink a lot of water: We should drink at least two litres of water every day. It keeps the muscles and other internal organs healthy. 4) Balanced diet: Our food helps our muscles strengthen, repair themselves and function properly. It is important to include all the nutrients like minerals and vitamins in our diet. Amazing Facts Our heart muscles never get to rest. They work non-stop till we die! Higher Order Thinking Skills (H.O.T.S.) We often hear of sportspersons getting injured. Do you know that most of their injuries are related to muscles? Let us learn about some common muscle injuries. 1) Strain: When a muscle has muscle strain in different ice pack on stretched too much, it causes parts of the body sprained leg muscle strain. For example, if we lift something too heavy like a big bucket of water, we might strain our muscle. It also happens when a muscle is used too much without rest. The treatment for strain includes applying an ice pack to the affected area. 2) Cramp: Sometimes a painful tightening of a muscle happens suddenly. This is a cramp. For example, if we play in warm or hot weather without drinking enough water, we get a cramp. It lasts from a few seconds to several minutes. It often occurs in the legs. Treatment for cramps is the massage of the affected area. cramp in leg 4 1/7/2019 3:09:34 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 130

3) Bruises: Bruises happen if our body hits any hard example of bruises while playing object. The area swells up. It forms a red mark that is painful, and movement becomes difficult. For example, when we fall from a bicycle or get hurt while playing football, we get bruises. Children mostly get their knees and elbows bruised while playing. We should wash the bruise properly and put a bandage on it. Do you know what a hamstring injury is? Find out. (Hint: Hamstrings are a group of leg muscles.) bandage on bruises hamstring muscles Muscular System 5 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 131 1/7/2019 3:09:34 PM

Lesson Respiratory System 2 Let Us Learn About r respiration and the respiratory system. U steps of respiration. A breathing rate and how blowing air can warm up or cool down things. H the importance of a stethoscope. Think Hold your finger under your nose. What do you feel on your finger? Remembering Have you ever noticed someone breathe? What does the person do? He or she breathes in and breathes out. This continues throughout the day. Taking in oxygen from the air and giving out carbon dioxide is called respiration. The organ system that helps in respiration is called the respiratory system. This system has the following parts: 1) A nose with a pair of openings called nostrils. 6 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 132 1/7/2019 3:09:34 PM

2) Windpipe (Trachea) 3) A pair of lungs: The sac-like lungs are located in the chest. They are protected by the rib cage. They occupy most of the space in the chest. Both lungs are not of the same size. The left lung is smaller than the right. 4) An elastic diaphragm: It is a dome-like muscle below the lungs. It separates the lungs from the stomach and intestine. nose mouth windpipe lungs diaphragm the human respiratory system Understanding breathe in breathe out How does respiration take place? There are two main steps of respiration: 1) breathing in (inhale) oxygen into the lungs 2) breathing out (exhale) carbon dioxide from the lungs The diaphragm has an important role. Breathing in and breathing out happen due to the up and down movement of the diaphragm. It moves down to take in oxygen. It moves up to release the carbon dioxide from the lungs. Respiratory System 7 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 133 1/7/2019 3:09:34 PM

Application BREATHING RATE Place your hands on your chest as you breathe. What is the pace of your breathing? Now stand and jump for five minutes. Keep your hands again on your chest. You are breathing hard and fast now. Why does this happen? We need to breathe because we need oxygen for many of our body functions. When we run, jump or play, we need more oxygen. So we breathe faster than usual. According to the difficulty level of the activity, the number of running makes us breathe times we breathe also increases. The faster we move, the faster faster we breathe. Usually, adults breathe about 18 times in a minute. Children breathe even faster. Count how many times you breathe in a minute. BLOWING air TO Warm UP OR COOL DOWN things Your mother has given you hot milk to drink. But you are getting late for school. What does she do? She blows into the glass of milk to cool it faster. We blow to cool the hot food or drink. The air from the mouth is cooler than the food. So it cools down the food. Does blowing always make things cold? Think, what will happen if you blow on an ice cream? Will it become colder? Try it. Why is the woman in the picture blowing on the fire? a woman blowing into a chulha Wood or fuels need air to burn. So, blowing into the fire makes the fire to burn faster and hotter. Amazing Facts Our body can withstand up to three weeks without food and one week without water. But, we can live only for three to four minutes without oxygen. 8 1/7/2019 3:09:34 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 134

Higher Order Thinking Skills (H.O.T.S.) Whenever we go to doctors, they keep a stethoscope on our chest. Then he or she asks us to take long breaths. Do you know why? A stethoscope is an instrument used to hear sounds of heartbeats and breathing. Doctors use it to check the health of our body. Our breathing and heartbeats change when we are unwell. stethoscope Respiratory System 9 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 135 1/7/2019 3:09:34 PM

Lesson Nervous System 3 Let Us Learn About r parts of the nervous system. u working of the nervous system. a role of our sense organs. h how the brain works with closed eyes. Think If we happen to touch or hold a hot vessel in our hand, what do we do? We let go of it immediately. How do we come to know that the vessel is hot and we should drop it? Remembering Our body is made up of organs which help us perform various functions. Do you think they perform these functions on their own? How do we walk? How do our legs move to walk? Our body has an organ system which controls all the body functions. It is called the nervous system. Without this system, our brain would be like jelly. It wouldn’t be able to perform any function. Let us learn about the different parts of the nervous system. 10 1/7/2019 3:09:34 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 136

1) The brain: The brain is located in the brain head. It is soft like jelly. It is covered and spinal cord protected by the skull. The skull is very hard. It protects the brain. The brain nerves manages the entire body, but weighs only about 1.5 kg. the human nervous system 2) The spinal cord: It is long and thin like a pipe. It starts from the lower part of the brain. It looks like a long tail of the brain. Along the way, nerves branch out from the spinal cord just like the branches of a tree from a tree trunk. The backbone encloses the spinal cord. 3) Nerves: The nerves are like wires. They are spread in our entire body like a spider’s web. They connect different body parts and organs to the spinal cord and to the brain. Understanding Our nervous system is like a postal service. Through the given pictures, let us understand how the nervous system works: 1) Sender (any organ or body part) gives the message to the postman (nerves). 2) Postman takes the message 1 2 3 (box) through the spinal cord (red scooter). 3) Postman gives the message to the brain. The brain reads these messages and decides what needs to be done. Accordingly, it gives messages in return. The brain tells what to do about the message. 4) The postman (nerves) returns 45 with the message from the brain through the spinal cord. nervous system working like a postal service Nervous System 11 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 137 1/7/2019 3:09:34 PM

5) Nerves then give the message to the receiver (same or different organ or body part). Once the body parts receive the message, they do what the message asks them to do. In our nervous system, the message can be about different parts of the body or about what is happening outside the body. The brain is the control centre of the body. The brain talks to the entire body through the spinal cord and nerves. It tells our body ‘what to do’ and ‘when to do it.’ All these steps take place at extremely high speed. This is why we can respond to things very fast. For example, when we see something in front of us, within a second we know what it is, how it looks like and how far or close it is. Application To control our body, the brain also needs to know what is happening outside our body. For example, when we walk, the brain needs to get the messages about the things in our way. How does the brain get these messages? For this, the sense organs work along with the nervous system. Eyes, ears, nose, tongue and skin are the organs that help us to sense the things around us. With the help of these organs, we see, hear, smell, taste and feel the things around us. Let us learn how these organs help us to sense with the help of the nervous system. When an object comes in front of us, the eyes send this information to the brain through the nerves. The brain reads this message and tells us what object it is. That is how we see. Similarly, if we smell or taste something, the five sense organs nose and tongue send a message to the brain through the nerves. Then, the brain tells us what kind of smell or taste it is. It also tells us whether the smell and taste are good or not. In the same way, the skin helps us to feel heat-cold, the rough-smooth and so on. Ears help us to hear with the help of messages from the brain. 12 1/7/2019 3:09:34 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 138

Amazing Facts In the human body, the right side of the brain controls the left side of the body, while the left side of the brain controls the right side. Higher Order Thinking Skills (H.O.T.S.) You have learnt that the five different sense organs help the brain to sense the things around us. Our brain identifies objects when the eyes send messages to the brain. Can the brain identify objects even without the help of the eyes? Let us do an activity. 1) Ask your parents, siblings or friends to keep different food items in different vessels. (This can be done in the classroom using the different tiffins during the lunch break.) 2) Close your eyes while they are putting these food items in the container. 3) Blindfold yourself. 4) Smell each food item. Try to identify it by its smell. 5) Try to guess the food by the feel of the food item. 6) If you could not find it out from the smell or feel, blindfolded child identifying then taste it. food item 7) Make a note of how many food items you could identify. From this activity, you will get to know that our brain can identify things with their smell, taste or feel (texture); even with our eyes closed. Nervous System 13 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 139 1/7/2019 3:09:35 PM

Lesson Floats, Sinks and Mixes 4 Let Us Learn About R the substances that float, sink and mix in liquids. u water as a universal solvent. a solvents other than water. h the effect of heat on solubility. Think If we add some sugar to water and stir it for some time, the sugar disappears. What happens to the sugar? Where does it go? Remembering When we add sugar to water or milk, the sugar disappears. It dissolves, and the water or milk looks same as before. We can know that the water or milk has sugar in it only when we taste it. In the above example, • Sugar that gets dissolved is a solute. • Water that dissolves something is a solvent. • Sugar syrup that we get after mixing water and sugar is a solution. sugar dissolves in water 14 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 140 1/7/2019 3:09:35 PM

Solvents can dissolve other substances in them. The substances that get dissolved are called solutes. When a solute dissolves in a solvent, a solution is formed. solute solvent solution Try this: Take a disposable plastic glass. Fill half of it with water. Add a drop of blue ink or neel (used at home to whiten clothes) in it. What happens to the water in the plastic glass? It turns blue. The blue ink or neel (solute) dissolves slowly in the mixing ink or neel changes the water (solvent) to turn it blue (solution). colour of water to blue Do all the things we add to water get dissolved in it? Try this: Take a small piece of paper. Put it in water. What happens? It paper boat floats on the remains near the surface. Stir the water. Does anything surface of water happen? No. It remains as it is. Paper does not dissolve in water. It floats on the surface. This is the reason why a paper boat also floats. Now, put a piece of chalk in a glass of water. What do you see? Does the chalk disappear in water? Does it float on the surface of water? No. It just goes down and settles at the bottom of the glass. The piece of chalk neither floats nor dissolves in water. It sinks in water. Substances that can dissolve in water are soluble substances. chalk piece sinks in water For example, salt, sugar, ink and so on. And ones that do not dissolve are insoluble. For example, wood, stones, sand, eraser, pencil and so on. Floats, Sinks and Mixes 15 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 141 1/7/2019 3:09:35 PM

Understanding Like water, oil is also a liquid. Can we dissolve sugar in it? Let us find out. Take one glass. Add some cooking oil to it. Now, add one spoon of sugar to it and stir. What do you observe? Sugar does not dissolve in oil. It remains at the bottom. Substances soluble in water may not be soluble in other liquids. As water can dissolve many substances, it is called the universal solvent. What will happen if we keep on adding any solute to water? Let us find out. Try this: Take half a glass of water. Add some salt and stir. Once it gets dissolved, add some more salt. Continue this process. salt remains undissolved After some time, the salt you add will remain at the bottom and will not dissolve further. Why is it so? This is because water gets filled with salt. It cannot take up any more salt. If you add some more water to it and stir, the salt that remained at the bottom will dissolve. after adding water, salt dissolved 1/7/2019 3:09:35 PM 16 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 142

Application We have learnt that water is a universal solvent. But it cannot dissolve some substances. Example: oil, stones, some wall paints and so on Try this: Take a glass of water. Add some cooking oil to it. What do you see? The water and oil remain separate. They do not mix. The oil floats on the surface of the water. Have you ever seen painters washing and cleaning their brushes? Do they wash it in water? No. Sometimes, the paint they use does not dissolve in water. So, they use a solvent like kerosene or petrol to wash some wall paints are not water soluble away the paint from the brushes. Have you ever seen your mother giving oil or grease stained clothes for dry cleaning? This is because the oil from the stains is not soluble in water. Some other solvents like petrol is used for dry cleaning. The oil from the stains gets dissolved in it, and the clothes get clean. Amazing Facts Have you ever wondered, why the soft drinks fizz when we fizzing soft drink can open the lid? These soft drinks have carbon dioxide dissolved in water under pressure. When we open a bottle or a can of soft drinks, the carbon-dioxide gas dissolved in the drink rushes out. This causes the fizz. Higher Order Thinking Skills (H.O.T.S.) We have learnt that we cannot dissolve something in water beyond a limit. Let us do an activity to understand why. Take three glasses. Take cold water in the first glass, normal water in the second glass and hot water in the third one. Add one spoon of sugar to each of them. Stir and observe the changes. Floats, Sinks and Mixes 17 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 143 1/7/2019 3:09:35 PM

The sugar in hot water disappears first. The normal water takes more time. Cold water takes the longest. dissolving sugar in cold water dissolving sugar in normal water dissolving sugar in hot water In all three glasses, the solvent and the solute are the same. Then why is there a difference in the speed of dissolving? The difference is due to heat. When water is heated, the heat energy causes the particles to start moving faster. Fast movement of the particles causes them to dissolve faster. Heating solvents like water or milk, allows us to dissolve more quantity of a solute in it. 18 1/7/2019 3:09:35 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 144

Inside the Lab – A Make sure you do these activities only with the help of a teacher or an adult. Activity A1: Respiratory System You will need: three balloons, scissors, knife, a large plastic bottle, two straws (that can be bent), clay and a rubber band You need to: 1) bend the straws at an angle. 2) insert the bent ends of the straws inside the balloons as shown in step 2. Secure them using the duct tape. 3) attach the straws to each other forming a ‘Y’ shape as shown in step 3. 4) add a ball of clay around the straight ends of the straws, leaving the holes of the straws open as shown in step 4. 5) place the straws into a bottle, and secure the clay around the opening of the bottle as shown in step 5. 6) cut the bottom of the bottle as shown in step 6. Cut off the neck of a balloon. Stretch the balloon to cover the bottom of the bottle and secure it with a rubber band. (The teacher should help the student while cutting.) 7) blow air into the straws. What do you see? When the air comes out from the bottle, what do you see? The balloons in the bottle act as lungs, and the balloon that is stretched acts as a diaphragm. When you blow air into the balloons, they expand. When the air comes out of the balloon, they return to their normal size. This is how we inhale oxygen and exhale carbon dioxide. NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 145 19 1/7/2019 3:09:35 PM

step 1 step 2 step 3 step 4 step 5 step 6 Activity A2: Water as a Universal Solvent We know that water is called a universal solvent as it dissolves more substances than any other liquid. Let us find out which of the following household items it will dissolve. You will need: four glasses of clean water, spoons, baking soda, pepper, flour, soap You need to: 1) line up the glasses of water and try to dissolve each of the substances by pouring one teaspoon of each substance into a separate glass. 2) stir using a spoon. 3) record your observations in the table given below. (Note: Do not try to put too much of any substance in the water.) Observation table: Name of the substance Dissolve/Does not dissolve 20 1/7/2019 3:09:35 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 146

Lesson Fruits and Seeds 5 Let Us Learn About R fruits and seeds. u t he dispersal and germination of seeds. a uses of seeds. h the collection of seeds. Think Shahid saw a baby mango plant in his backyard. It was not there a few days back. He wondered how the new baby plant came out of the soil. Can you guess? baby mango plant Remembering Shahid wanted to know from where the baby mango plant had sprouted. He removed the litter and some soil around the baby plant. Then, he could see that the baby plant had sprouted from a mango seed buried in the soil. Shahid went to his mother and told her about the baby plant. His mother told him that plants make fruits and seeds to produce new baby plants. Let us learn about fruits and seeds and how they produce new plants. NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 147 21 1/7/2019 3:09:35 PM

Most of the plants around us produce a pomegranate flower developing into a fruit flowers. Most of these flowers develop into fruits with the help of insects and birds. For example, most mango flowers change into mangoes. Pomegranate flowers change into pomegranates. Most fruits contain seeds inside them. Some have only one seeds inside seed outside seed, while some fruits have a few seeds. There are some the apple the cashew fruits that have many seeds, while some other fruits do not have any seeds. You might have seen grapes without seeds. Some fruits have seeds outside them. For example, cashew has a seed outside the fruit. Like fruits, seeds also vary in shape, size and colour. Most of a mango with a papaya with the fruits are fleshy, tasty and nutritious. So, animals, birds seed inside many seeds and humans use them as food. Understanding Seeds can form new plants. When a seed grows into a new plant, it is called germination. A seed needs soil, air, water and nutrients to germinate. How germination of a seed does a seed reach the soil? When the fruits are ripe, they fall off from the plant. After a few days, the fruit may decay or dry up, and the seeds get exposed. Have you seen ripe mangoes fall from the tree? What will happen if all the seeds fall below the tree and germinate there? They will not have enough space to grow. The nutrients in the soil will not be enough for all of them to grow. So, seeds of plants need to be spread to different places. This spreading of seeds from the plants is known as the dispersal of seeds. How does this dispersal take place? 2 Water: Seeds of the plants like lotus or coconut, which grow in or around 1 Wind: Some seeds are dandelion seeds carried away by the gliding in the air water bodies are dispersed by water. These type of seeds float on water. wind. For example, seeds of dandelion plants. Have coconut you seen any fluffy seeds dispersed gliding in the air? by water 22 1/7/2019 3:09:35 PM NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 148

3 Animals: Seeds of some plants are sticky. They get birds eat fruits, and attached to the body of animals. When these animals disperse the seeds through their beaks wander from one place to another, the seeds attached to their bodies may fall off at different places. For example, grass and droppings seeds. Some birds eat fruits. Sometimes seeds fall off accidentally from their beaks. Birds may also spit the seed after eating the fruit. And sometimes, seeds reach the soil through bird droppings. Animals like bats are also involved in the dispersal of seeds of the banyan and guava trees. Human beings also help in the dispersal of seeds. For example, seeds get stuck to the clothes and shoes of farmers and are dispersed. 4 Explosion: Seeds of some plants are After dispersal, seeds reach the soil. In the dispersed by fruit explosion. soil, they germinate and turn into a new plant. For example, ladies’ fingers and mustard. Let us see how: ladies’ fingers explode to disperse the seeds Seeds need moisture, air and the right amount of warmth to germinate and grow. Until they have these conditions, the seeds do not sprout. Once the seeds get the right conditions, they turn into plantlets. They then grow into big plants. Application We have learnt that new plants grow from seeds. If we observe a sprouting seed, we can see that the sprout does not have roots. Then, from where does it get the nutrients to grow? The small plant absorbs the food from within the seed till it develops roots. Seeds have food stored inside them. Due to this, we also use different types of seeds as our food. Let us see some uses of seeds. 1) Cereals, pulses and sprouts that we use are the seeds of plants. For example, rice, moong, chana and so on. You may have seen sprouts. They are the germinated pulses. 2) The nuts we eat are the seeds of plants. For example, groundnut, cashew nut and so on. 3) Some of the spices we use are the seeds of plants. For example, pepper. 4) We extract oil from groundnut, mustard, coconut and other such seeds. Fruits and Seeds 23 NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 149 1/7/2019 3:09:35 PM

pulses sprouts nuts seed used as oilseed – mustard spice – pepper Amazing Facts Atlantic giant pumpkins are the largest fruits ever grown on earth. Atlantic giant pumpkin Higher Order Thinking Skills (H.O.T.S.) There are numerous variety of seeds in the world. Let us find out the different types of seeds in our surroundings. 1) Collect different varieties of seeds available in your house and surroundings. Try to collect at least ten different types of seeds. 2) Separate the seeds based on their shape, size, colour and so on. 3) Paste them directly in your scrapbook, or you can put them in small bags to make samples. 4) Find out the use of these seeds to us, if any. 5) Also find the way in which their dispersal happens. 24 variety of seeds NR_BGM_9789386663498 MAPLE G05 INTEGRATED TEXTBOOK TERM 1_Text.pdf 150 1/7/2019 3:09:35 PM