Solution: Two numbers and their sum are given. We can use some situation to frame the story sum. Step 1: Think of a situation. Here, let us take the number of different fruits such as oranges and apples in a basket. Step 2: Write the story in your words. There were 32 oranges and 22 apples in a fruit basket. How many fruits were there in all? Maths Munchies Trick to add 3-digit numbers quickly: 355 + 152 213 Step 1: 355 + 152 can be written as 350 + 5 + 150 + 2 In this step, 355 is split into 350 and 5 and 152 into 150 and 2 Step 2: 350 + 150 = 500 5+2=7 500 + 7 = 507 So, 355 + 152 = 507. Connect the Dots EVS Fun Count the total number of fingers and toes you have. Also count the same for the other members of your family. Write the total number of fingers and toes that you have counted. Addition 47 NR_BGM_9789388700948 PASSPORT G02 MATHS TEXTBOOK PART 1_Text.pdf 51 12/19/2018 10:52:50 AM
English Fun Let us read a funny poem about Addition. I got a new dog, Addition’s his name, He lives in the kitchen, eating’s his game! He weighed in at 4 pounds, but added 4 more, 8 pounds was the sum, he couldn’t squeeze out the door... 8 pounds? Not big! So he added 8 more, The sum was 16, he was growing galore! 16’s enough! I yelled, “Don’t get bigger! 16 more pounds, was too heavy to figure! Now Addition’s so big, it’s just a sad fact, I’ll need dog, Addition, to learn to subtract. Drill Time Concept 4.1: Add 2-digit and 3-digit Numbers 1) Add 2-digit numbers with regrouping. a) 77 + 13 b) 26 + 35 c) 19 + 35 d) 49 + 12 e) 55 + 25 2) Add 3-digit numbers without regrouping. a) 166 + 111 b) 612 + 352 c) 181 + 315 d) 490 + 100 e) 812 + 121 3) Word problems a) F arah has 11 balloons and her friend has 29 balloons. How many balloons do they have in all? b) A khil had 120 pens in one box and 121 pens in another box. How many pens did he have in all? A Note to Parent Take your child to the supermarket. Ask them to pick up three things of their choice and find the total cost of the items. 48 12/19/2018 10:52:50 AM NR_BGM_9789388700948 PASSPORT G02 MATHS TEXTBOOK PART 1_Text.pdf 52
Chapter Subtraction 5 I Will Learn About • subtracting 2-digit and 3-digit numbers. • properties of subtraction. • mental Maths techniques for subtraction. Concept 5.1: Subtract 2-digit and 3-digit Numbers I Think David got 83 candies from his parents for his birthday. He gives 27 candies to his friend Neha. How can David find the number of candies left with him without counting? 5.1 I Recall In class 1, we have learnt to subtract using a number line and also by counting. We have also learnt subtraction using the place value chart. Let us solve the following to recall the concept of subtraction. NR_BGM_9789388700948 PASSPORT G02 MATHS TEXTBOOK PART 1_Text.pdf 53 49 12/19/2018 10:52:50 AM
Count, write and subtract the numbers in the boxes. 12/19/2018 10:52:50 AM a) b) c) d) 50 NR_BGM_9789388700948 PASSPORT G02 MATHS TEXTBOOK PART 1_Text.pdf 54
5.1 I Remember and Understand 9. Subtraction of 2-digit numbers with regrouping Place values of digits in 2-digit numbers are tens and While subtracting, ones. Sometimes, subtracting 2-digit numbers needs always start from regrouping. Let us see some examples. the ones place. Example 1: Subtract 48 from 56. Solution: To subtract, follow these steps: Steps Solved Solve these Step 1: Write the numbers according to their TO TO places. Subtract the digits in the ones place. But, we cannot subtract 8 from 6. So, we 56 4 4 have to regroup the tens. –4 8 –3 8 5 tens = 4 tens + 1 ten. We know that 1 ten = 10 ones. Step 2: Add 1 ten to the ones place. So, TO TO it becomes 16 ones. Also, subtract 1 ten 4 16 from the tens place (that is, 5 – 1 = 4). Now, 56 9 8 subtract 8 from 16. That is, 16 – 8 = 8. Write –4 8 –3 9 the difference in the ones place. (Note: You cannot subtract from zero. You must borrow 8 from the next place instead. For example, for subtracting 27 from 40, you cannot subtract 7 from 0. Hence, you borrow 1 from 4 (the tens place of 40) to give 10 for 0 and 3 for 4.) Step 3: Subtract the digits in the tens place. TO TO That is, 4 – 4 = 0. Write the difference in the 4 16 tens place. 56 8 6 –4 8 –2 7 So, 56 – 48 = 8. 08 Subtraction 51 NR_BGM_9789388700948 PASSPORT G02 MATHS TEXTBOOK PART 1_Text.pdf 55 12/19/2018 10:52:50 AM
Subtract 3-digit Numbers without regrouping Let us understand how to subtract 3-digit numbers through an example. Example 2: Subtract 141 from 943. Solution: To subtract the given numbers, follow these steps: Steps Solved Solve these Step 1: Arrange the numbers HTO HTO according to their place values. 943 784 –1 4 1 –3 3 2 HTO HTO 496 Step 2: Subtract the digits in the 943 –2 6 2 ones place. Write the difference in –1 4 1 the ones place. That is, 3 – 1 = 2. 2 HTO HTO 636 Step 3: Subtract the digits in the 943 –1 3 0 tens place. Write the difference in –1 4 1 the tens place. That is, 4 – 4 = 0. 02 Step 4: Subtract the digits in HTO HTO the hundreds place. Write the 943 846 difference in the hundreds place. –4 2 0 That is, 9 − 1= 8. –1 4 1 So, 943 – 141 = 802. 802 Properties of subtraction 1) Zero property: When we subtract 0 from a number, the difference is the number itself. For example, 12 – 0 = 12 52 12/19/2018 10:52:50 AM NR_BGM_9789388700948 PASSPORT G02 MATHS TEXTBOOK PART 1_Text.pdf 56
2) Before numbers property: When we subtract 1 from a number, we get the number that is just before it. For example, 35 – 1 = 34 3) Subtracting a number from itself: When we subtract a number from itself, the difference is 0. For example, 35 – 35 = 0 Train My Brain a) Subtract 0 from 12. b) Find the difference between 50 and 1. c) What is the difference when a number is subtracted from itself? 5.1 I Apply We use the concept of subtraction to solve some real-life situations. Let us see a few examples. Example 3: A class of 390 students is divided in red and blue groups. Among them, 150 students are in the red group. How many students are in the blue group? Solution: Number of students in the class = 390 HTO Number of students in red group = 150 39 0 Number of students in blue group = 390 – 150 −15 0 So, there are 240 students in the blue group. 2 4 0 Example 4: There are 52 candies in a jar. Children ate up 37 of TO them. How many candies are left in the jar? S olution: Number of candies in a jar = 52 4 12 Number of candies eaten by children = 37 52 Number of candies left in the jar = 52 – 37 −3 7 So, there are 15 candies left in the jar. 15 Subtraction 53 NR_BGM_9789388700948 PASSPORT G02 MATHS TEXTBOOK PART 1_Text.pdf 57 12/19/2018 10:52:50 AM
5.1 I Explore (H.O.T.S.) Let us now learn to frame a story sum based on subtraction. Example 5: Given 163 −120 = 43, frame a story sum. Solution: Two numbers and their difference are given. We can use a situation to frame the story sum. Step 1: Think of a situation. For example, Shyam takes some chocolates to school on his birthday. Since it is subtraction, these chocolates should be given away. Step 2: Write the story in your words. Shyam takes 163 chocolates to school on his birthday. He shares 120 chocolates among his classmates. How many chocolates are left with him? Concept 5.2: Subtract Two 1-digit Numbers Mentally I Think David had ` 9 with him. He gave ` 4 to his sister. How much amount was left with David? Can you find out without using pen and paper? 5.2 I Recall To subtract numbers mentally, we need to remember the correct order of numbers. Also we need to practise backward counting of numbers in the correct order. 54 12/19/2018 10:52:50 AM NR_BGM_9789388700948 PASSPORT G02 MATHS TEXTBOOK PART 1_Text.pdf 58
Let us recall how to write numbers backwards from 20 to 1. 20 1 5.2 I Remember and Understand Let us understand how to subtract two 1-digit numbers mentally, through this example. If the two given Example 6: Subtract mentally: 2 from 5 numbers are the Solution: To subtract the given numbers same, the answer is mentally, follow these steps: zero. Steps Solved Solve this 2 from 5 4 from 9 Step 1: Keep the bigger number in mind. The bigger number is The bigger number is 5. So, keep 5 in mind. _____. So, keep _______ in mind. Step 2: Keep as many fingers The smaller number is The smaller number is open as the smaller number. 2. So, keep 2 fingers _____. So, keep _______ open. fingers open. Step 3: Begin counting The number before The number before ___ backwards from the bigger 5 is 4. Count 2 fingers is ___. Count ___ fingers number. Fold as many fingers backwards as 4 backwards as ___, ___, as the smaller number. and 3. ___, and ____. Step 4: Write the number The difference of 5 The difference of 9 and obtained in step 3 as the and 2 is 5 – 2 = 3. 4 is 9 – 4 = ___. difference of the given numbers. Subtraction 55 NR_BGM_9789388700948 PASSPORT G02 MATHS TEXTBOOK PART 1_Text.pdf 59 12/19/2018 10:52:50 AM
Train My Brain c) 4 – 4 Solve the following mentally: a) 8 – 6 b) 7 – 3 5.2 I Apply We have seen how easy it is to subtract 1-digit numbers mentally. It is important to use mental subtraction of numbers in some real-life situations. Let us see a few examples. Example 7: Meena has 7 chocolates with her. She gave 3 of them to her sister. How many chocolates are left with Meena? Solution: Number of chocolates Meena has = 7 Number of chocolates Meena gave to her sister = 3 The bigger number is 7. The smaller number is 3. So, we keep the bigger number in the mind. We keep the smaller number on the fingers. That is, 7 in the mind, 3 on the fingers. But when we subtract we count backwards. Before 7, we count 3 fingers backwards as 6, 5 and 4. So, 4 chocolates are left with Meena. Example 8: Sameer is on an 8-day long vacation to Shimla with his family. He has spent 5 days there. How many days are left in his vacation? Solution: Number of days of vacation = 8 Number of days of the vacation spent = 5 The bigger number is 8 and the smaller number is 5. So, we keep the bigger number (8) in the mind. Keep the smaller number (5) on the fingers. 56 12/19/2018 10:52:50 AM NR_BGM_9789388700948 PASSPORT G02 MATHS TEXTBOOK PART 1_Text.pdf 60
But when we subtract, we count backwards. Before 8, we count 5 fingers as 7, 6, 5, 4 and 3. So, 3 days of Sameer’s vacation are left. 5.2 I Explore (H.O.T.S.) Let us now see an example involving mental addition and subtraction together. Example 9: Priya had 6 pencils. She gave 2 pencils to her brother and 1 pencil to her sister. How many pencils did she give in all? How many pencils are left with Priya now? Solution: Total number of pencils with Priya = 6 Number of pencils she gave her brother = 2 Number of pencils she gave her sister = 1 We need to find the total number of pencils Priya gave away. So, add the number of pencils she gave to her brother and to her sister. The bigger number is 2 and the smaller number is 1. So, keep 2 in mind and 1 on the fingers. After 2, count 1 finger ahead. So, Priya gave away 3 pencils. Now, we need to find the number of pencils left. So, for this, subtract the number of pencils given away from the total pencils. The bigger number is 6 and the smaller number is 3. So, keep 6 in mind and 3 on fingers. Counting 3 fingers backwards from 6 we get 3. So, 3 pencils are left with Priya. Subtraction 57 NR_BGM_9789388700948 PASSPORT G02 MATHS TEXTBOOK PART 1_Text.pdf 61 12/19/2018 10:52:50 AM
Maths Munchies 213 Subtraction of 2-digit numbers from 100: 1 0 0 − 8 6 from 9 Consider the example 100 – 86. = 1 4 from 10 In this example, we have subtracted 8 from 9 and then 6 from 10 which results in 14. This trick helps in faster calculations. Connect the Dots English Fun Let us read a poem about Subtraction. Here we go subtracting numbers, To find the difference Subtracting numbers, subtracting Next you take away a part, numbers Away a part, away a part, Here we go subtracting numbers, Next you take away a part, To find the difference To find the difference First you start with the whole, You have found the other part, With the whole, with the whole, The other part, the other part, First you start with the whole, You have found the other part, That is the difference. 58 12/19/2018 10:52:51 AM NR_BGM_9789388700948 PASSPORT G02 MATHS TEXTBOOK PART 1_Text.pdf 62
EVS Fun You have invited 15 people. Six of them are your friends. Also, there is one uncle, one aunt and three cousins. Your parents and grandparents are also there. If we separate all the extended family members, how many guests will remain? Drill Time Concept 5.1: Subtract 2-digit and 3-digit Numbers 1) Subtract 2-digit numbers with regrouping. a) 25 – 18 b) 37 – 29 c) 48 – 19 d) 56 – 27 e) 90 – 25 2) Subtract 3-digit numbers without regrouping. a) 356 – 256 b) 197 – 106 c) 786 – 122 d) 476 – 111 e) 854 – 221 3) Word problems a) Vivaan has 33 cups in a box. He removed 17 of them and placed on the table. How many cups are left in the box? b) B aiju has 142 marbles with him in a basket. Out of these, he removed 100. How many marbles are left in the basket? Concept 5.2: Subtract Two 1-digit Numbers Mentally 4) Subtract the following mentally: a) 3 from 9 b) 2 from 7 c) 2 from 4 d) 7 from 8 e) 1 from 2 Subtraction 59 NR_BGM_9789388700948 PASSPORT G02 MATHS TEXTBOOK PART 1_Text.pdf 63 12/19/2018 10:52:51 AM
Drill Time 5) Word problems a) Sana drew 8 balloons out of which she coloured 6 red and the rest blue. How many balloons were coloured blue? b) R ohan made a bunch of 5 flowers out of which 1 flower fell down from his hand. How many flowers are left in his hand? A Note to Parent Give your child some toffees. Now play as follows: a) A sk for 0 toffees. Then, ask the number of toffees left. b) Ask them to give you one toffee. Then, ask to count the number of toffees left. c) A sk them to give you different number of toffees and ask to count the number of toffees left. 60 12/19/2018 10:52:51 AM NR_BGM_9789388700948 PASSPORT G02 MATHS TEXTBOOK PART 1_Text.pdf 64
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