Active Maths CB G3 Inside_LR

Mathematics 3Coursebook SCHOLASTIC

TO 1 Numbers to 10,000 Let’s Revise 1. Look at the place value table. Then, fill in the blanks. H T O 743 SCHOLASTIC a) 743 = hundreds tens ones b) 743 is read as . c) The digit 7 is in the place. It stands for . d) The digit 4 is in the place. Its place value is . 2. Compare the numbers 371, 525 and 306. a) Fill in the blanks with > or <. 371 525 306 525 371 306 b) Arrange the numbers in increasing order. . . , , 3. Complete the table. Before Between After 649 401 a) 399 b) 740 c) 738 4. Fill in the missing numbers. . b) 10 less than 900 is a) 1 more than 345 is . d) 100 less than 789 is c) 100 more than 593 is 5. Complete the number line. 170 171 172 175 177 178 6 more less © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

1 22 2 ? 3 44 3456 1 1  Thousands, Hundreds, Tens and Ones 1.1  Reading and writing numbers SCHOLASTIC2 thousands3 hundreds 5 tens 4 ones 1000 1000 100 100 100 10 10 10 10 10 1111 2000 2354 Count on from 1000. 300 1000, 2000, 2100, 2200, 2300, 50 2310, 2320, 2330, 2340, 2350, 4 2351, 2352, 2353, 2354 2354 is read as two thousand three hundred fifty-four. Exercise 1 1. Write the number. a) b) 7 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

2. Match. • five thousand seven hundred twenty • five thousand two hundred seventy 5702 • • five thousand seven hundred two 5207 • • five thousand two hundred seven 5720 • 5270 • 1.2 Identifying values of digits 4358 is a 4-digit number. 4358 8 The digit 8 stands for 8. 5 0 The digit 5 stands for 50. 3 0 0 The digit 3 stands for 300. 4 0 0 0 The digit 4 stands for 4000. SCHOLASTIC Thousands Hundreds Tens Ones (Th) (H) (T) (O) 43 5 8 In 4358, the digit 8 is in the ones place and its place value is 8. The face value of the digit 8 is 8. In 4358, the digit 5 is in the tens place and its place value is 50. The face value of the digit 5 is 5. In 4358, the digit 3 is in the hundreds place and its place value is 300. The face value of the digit 3 is 3. In 4358, the digit 4 is in the thousands place and its place value is 4000. The face value of the digit 4 is 4. The face value of a digit in a number is the digit itself. It remains the same irrespective of its place. 8 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

Exercise 2 1. Look at the place value table below. Then, fill in the blanks. Th H T O 6135 a) The digit 1 is in the place. b) The digit 3 stands for . SCHOLASTIC c) The digit in the thousands place is . . d) The place value of the digit 5 is . . e) The face value of the digit 6 is f) The face value of the digit 3 is 1.3 Writing numbers in expanded form and standard form 1000 1000 100 100 11 There are no tens 1000 1000 100 100 11 in this number. 1000 100 100 11 5708 is read as five 100 11 ­thousand seven 5 thousands ­hundred eight.     7 hundreds    8 ones Th H T O 5708 57 0 8 5000 + 700 + 0 + 8 = 5708 expanded form standard form © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 9

Exercise 3 1. Write in expanded form. a) 3293 = + + + + + b) 5927 = + 2. Write in standard form. b) 3000 + 200 + 90 + 1 = a) 6000 + 500 + 10 + 8 = SCHOLASTIC 1.4 Forming, comparing and ordering numbers a) Form 4-digit numbers using the digits 4, 5, 7 and 8. Use each digit only once. Th H T O Th H T O 4578 5478 4587 5487 4758 5748 4785 5784 4857 5847 4875 5874 Th H T O Th H T O 7458 8457 7485 8475 7548 8547 7584 8574 7845 8745 7854 8754 We can form twenty-four 4-digit numbers using the digits 4, 5, 7 and 8. 10 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

b) Compare 4539 and 6274. Th H T O 4539 4 5 3 9 6274 6 2 7 4 Compare the thousands. We can also say that 6 thousands is greater than 4 thousands. 4539 is smaller than 6274. So, 6274 is greater than 4539. 4539 < 6274 6274 > 4539 c) Compare 5307, 3614 and 5351. SCHOLASTIC Th H T O 5307 5 3 0 7 3614 3 6 1 4 5351 5 3 5 1 First, compare the thousands. 3 thousands is smaller than 5 thousands. 3614 is the smallest. Next, compare 5307 and 5351. Th H T O 5307 5 3 0 7 5351 5 3 5 1 First, compare the thousands. 11 They are the same. Next, compare the hundreds. They are the same. Then, compare the tens. 0 tens is smaller than 5 tens. 5307 is smaller than 5351. 5351 is the greatest number. If we arrange the numbers in increasing order, we have: 3614, 5307, 5351. (smallest) If we arrange the numbers in d­ ecreasing order, we have: 5351, 5307, 3614. (greatest) © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

Exercise 4 1. Form four 4-digit numbers using the digits 5, 0, 3 and 6. Use each digit only once. Placing 0 in the thousands place would give a 3-digit number. 2. Fill in the circles with < or >. a) 4135 5134 SCHOLASTIC b) 2847 2748 c) 9203 9032 d) 7516 7561 3. Circle the smallest number. Cross out the greatest number. a) 2215 1704 3860 b) 9853 7692 9081 c) 7646 6754 7532 d) 3479 4025 3476 Practice 1 1. Write the numbers. a) seven thousand one hundred thirty-nine b) one thousand eight hundred four c) three thousand five hundred ten d) three thousand seven hundred fifteen e) nine thousand three hundred eighty-nine 2. Write the numbers in words. a) 4006 b) 9257 c) 8013 d) 8241 e) 6209 12 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

3. Fill in the missing numbers. b) 1426 = 1000 + + 20 + 6 a) 1000 + 80 + 5 = d) 5904 = + 900 +4 c) 2000 + 100 + 8 = f) 2030 = 2000 + e) 7000 + 10 + 2 = 4. Fill in the blanks. a) In 3470, the digit 4 is in the place. b) In 8129, the digit is in the tens place. SCHOLASTIC c) In 7286, the digit has a place value of 7000. d) In 9305, the digit 0 has a place value of . e) In 7596, the face value of the digit 9 is . 5. Fill in the circles with > or <. a) 3527 1479 b) 8374 6372 c) 4280 4652 d) 6401 6483 e) 8099 8009 f) 7299 7294 6. Arrange the numbers in increasing order. 7289 7198 7829 a) 8475 1938 8623 9182 b) 7189 9075 9305 9370 c) 6352 7483 6027 7408 d) 9375 7. Arrange the numbers in decreasing order. 4805 9054 9540 a) 8719 8745 5298 6273 b) 4580 3649 3645 8730 c) 4632 6842 6840 4362 d) 8736 8. Form all possible 4-digit numbers using the digits 1, 4, 5 and 7. Then, write the smallest 4-digit and the greatest 4-digit numbers formed. I know how to identify the place value and face value of digits in 4-digit numbers read and write a number within 10,000 form, compare and order 4-digit numbers w rite a 4-digit number in expanded form and standard form © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 13

2  Number Patterns 2.1  Finding ‘more than’ and ‘less than’ Th H T O 2453 a) Th O What number is 1000 more SCHOLASTICHT than 2453? 2453 + 1000 3453 1000 more than 2453 is 3453. b) Th H T O What number is 100 less than 2453? 2453 – 100 2353 100 less than 2453 is 2353. c) Th H T O What number is 10 more than 2453? 2453 + 10 2463 10 more than 2453 is 2463. d) Th H T O What number is 1 less than 2453? 2453 – 1 2452 1 less than 2453 is 2452. We subtract 1 to find ‘1 less than’ or the number ‘before’. We add 1 to find ‘1 more than’ or the number ‘after’. 14 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

Exercise 5 1. Fill in the missing numbers. a) 10 more than 3508 is . b) 100 less than 1423 is . Th H T O c) 1000 less than 7759 is . d) comes before 5674. e) is between 7359 and 7361. SCHOLASTIC f) comes after 7562. 2.2  Number patterns a) Count in steps of 10 from 1238 to 1258. 1238 + 10 1248 + 10 1258 1248 is 10 more than 1238. 1258 is 10 more than 1248. 1000 1000 1000 200 200 200 3090 is 1000 more than 2090. 30 40 50 4090 is 1000 more than 3090. 8 8 8 b) Count in steps of 1000 from 2090 to 6090. 20+9100,03009+01,0400090, 5090, 6090 c) Count backwards in steps of 100 from 5816 to 5416. – 100 – 100 5716 is 100 less than 5816. 5616 is 100 less than 5716. 5816, 5716, 5616, 5516, 5416 Exercise 6 1. Complete the number patterns. a) 1004, 1104, 1204, , , 1504 + 100 + 100 1004, 1104, 1204 b) 1798, 2798, 3798, , , 15 c) 9869, 9868, , , 9865, d) 3748, 3738, , 3718, 3708, © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

Practice 2 1. Fill in the missing numbers. a) 100 more than 9716 is . b) comes before 5608. c) is 1000 more than 1365. d) is 100 less than 6824. e) 8517 comes after . f) 3432 is more than 3422. g) 1158 is less than 1168. h) 7046 is less than 8046. 2. Complete the number patterns. SCHOLASTIC a) 6357, 6358, 6359, , 6361, b) , 9442, 9342, 9242, , 9042 c) 7931, , 7951, 7961, , d) 7450, , , 4450, 3450, 2450 e) 5972, 5971, , , 5968, 5967 f) , 2050, 2040, , 2020, 2010 I know how to find 1, 10, 100 or 1000 less than a given number find 1, 10, 100 or 1000 more than a given number c omplete number patterns 3  Rounding Numbers 3.1  Reading number lines The numbers are arranged in increasing order from left to right on the number line. W XY Z 1000 1500 2000 2500 W represents 1200. There are 10 equal intervals between 1000 X represents 1600. and 2000. Y represents 1800. Each interval stands for 100. Z represents 2400. Count in steps of 100. 1000, 1100, 1200… 16 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

Exercise 7 1. Complete the number lines. a) 4010 4015 4020 b) SCHOLASTIC5000 5500 6000 3.2  Rounding numbers to the nearest ten a) Round the numbers 43, 49 and 55 to the nearest ten. 43 49 55 40 50 60 43 is between 40 and 50. Round 43 to the nearest ten. It is nearer to 40 than to 50. 43 is approximately 40. 43 is 40 when rounded to the nearest ten. ≈ is the approximation sign. 43 ≈ 40 43 is approximately 40. 49 is between 40 and 50. 55 is halfway between 50 and 60. It is nearer to 50 than to 40. Take 60 to be the nearest ten. 49 is 50 when rounded to the 55 is 60 when rounded to the nearest ten. nearest ten. 49 ≈ 50 55 ≈ 60 49 is approximately 50. 55 is approximately 60. © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 17

b) Round 197 to the nearest ten. 197 190 195 200 197 is between 190 and 200. It is nearer to 200 than to 190. 197 is 200 when rounded to the nearest ten. 197 ≈ 200 SCHOLASTICc) Round 3805 to the nearest ten. 3805 3800 3805 3810 3805 is halfway between 3800 and 3810. 3805 is 3810 when rounded to the nearest ten. 3805 ≈ 3810 Exercise 8 1. Round each number to the nearest ten. a) 24 b) 1275 20 25 30 1270 1275 1280 24 ≈ 1275 ≈ 3.3 Rounding numbers to the nearest hundred a) Round 680 to the nearest hundred. 680 600 650 700 680 is more than halfway between 600 and 700. It is nearer to 700 than to 600. 680 is 700 when rounded to the nearest hundred. 680 ≈ 700 18 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

b) Round 5327 and 5350 to the nearest hundred. 5327 5350 5300 5350 5400 5327 is less than halfway between 5300 and 5400. It is nearer to 5300 than to 5400. 5327 is 5300 when rounded to the nearest hundred. 5327 ≈ 5300 5350 is halfway between 5300 and 5400. 5350 is 5400 when rounded to the nearest hundred. 5350 ≈ 5400 SCHOLASTIC Exercise 9 1 . Round each number to the nearest hundred. a) 8 390   8300 8350 8400 8390 ≈ b) 9023 9000 9050 9100 9023 ≈ List the numbers that can be rounded to the nearest ten to get 100. © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 19

Practice 3 1. Complete the number lines. a) 8150 8200 8250 b) SCHOLASTIC900 1000 1100 2. Round the numbers. a) 67 children took part in a summer camp. Round the number of children to the nearest ten. b) James spent ` 3483 on a chair. Round the amount he spent to the nearest 10 rupees. c) Beena drove 285 kilometres to get to the airport. Round the distance to the nearest 10 kilometres. 3. The table shows the cost of a bus ticket from Delhi to different cities in India. Round each amount to the nearest ` 100. Destination Cost Rounded to the nearest ` 100 Jaipur ` 483 Manali ` 1101 Nainital ` 958 Mumbai ` 2739 round 2-digit, 3-digit and 4-digit numbers I know how to to the nearest ten represent numbers on number lines round 3-digit and 4-digit numbers to the nearest hundred 20 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

Chapter Review 1. Write the numbers in words. a) 5692 b) 1009 c) 3092 d) 7106 2. Complete the table. Standard form Expanded form a) 7041 b) c) 8207 d) e) 3512 SCHOLASTIC 9000 + 10 + 9 5000 + 1 3. Complete the number patterns. a) 1112, , 1106, 1103, , b) 8998, , 9002, 9004, , c) , , 3474, 3472, , d) , , , 8490, 8495, , 8505 4. Fill in the missing numbers. a) Seven hundred eighty-four rounded to the nearest ten is . b) T hree hundred forty-five rounded to the nearest hundred is . c) F ive hundred sixty-five rounded to the nearest ten is . d) Nine thousand one hundred five rounded to the nearest hundred is . 5. Compare the numbers using > or <. a) 5892 five thousand eight hundred ninety-five b) 1 more than 4019 10 more than 4000 c) 100 more than 8100 1000 less than 7000 d) 100 less than 8990 1000 more than 7915 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 21

6. Form any three 4-digit numbers using the digits 1, 5, 0 and 7. Use each digit only once. Arrange the numbers in increasing order. 7. Form the greatest possible number using the digits 2, 3, 5 and 7 using each digit only once, such that the place value and face value of the digit 7 remains the same. 8. Kavita says that the following numbers are in increasing order. 6720, 6072, 7126, 7162 Is she correct? Give reasons for your answer. 9. Mona says that 408 when rounded to the nearest ten and nearest hundred is 400. Is she correct? Give reasons for your answer. SCHOLASTIC Maths Lab Activity Forming numbers Roll a die 4 times. Form a 4-digit number using the digits that come up. Write the number in words and in expanded form. Round the number to the nearest ten and hundred. Form 5 such numbers by rolling the die. Repeat all the given steps. Arrange the 5 numbers formed in decreasing order. For example, Number Number in words Expanded form Nearest Nearest 6000 + 300 + 20 + 1 ten hundred 6321 six thousand three hundred 6320 6300 twenty-one Decreasing order: , , , , 22 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

TO 2 Addition and Subtraction Let’s Revise 1. Fill in the missing numbers. sum SCHOLASTIC difference a) 32 + 5 = The sum of 32 and 5 is . b) 32 – 5 = The difference between 32 and 5 is . 2. Add. a) H T O b) H T O c) H T O 645 529 629 +243 +382 +175 3. Subtract. a) H T O b) H T O c) H T O 384 800 952 –263 –236 –378 4. Leela has 275 stickers. Her friend gives her 58 more. How many stickers does she have now? 275 58 275 + 58 = ? Leela has stickers now. © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 23

1 Adding Ones, Tens, Hundreds and Thousands 1.1  Adding without and with regrouping a) Find the sum of 2431 and 1426. Th H T O 2431 1426 SCHOLASTIC 3857 1 Add the ones. 2 Add the tens. Th H T O Th H T O 24 31 24 31 +1 4 2 6 +1 4 2 6 7 57 3 Add the hundreds. 4 Add the thousands. Th H T O Th H T O 2 431 24 31 +1 4 2 6 +1 4 2 6 857 38 57 2431 + 1426 = 3857 The sum of 2431 and 1426 is 3857. 24 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

b) Find the sum of 1634 and 2085. T O Th H 1634 2085 SCHOLASTIC3719 1 Add the ones. 2 Add the tens. Th H T O Th H T O 10 tens = 1 hundred 16 34 +2 0 8 5 1 9 16 34 +2 0 8 5 19 Regroup 11 tens into 1 hundred 1 ten. 3 Add the hundreds. 4 Add the thousands. Th H TO Th H TO 1 1 34 1 1 34 +2 85 +2 85 6 19 6 19 0 3 0 7 7 1634 + 2085 = 3719 The sum of 1634 and 2085 is 3719. © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 25

c) Find the sum of 2793 and 3408. T O Th H 2793 3408 SCHOLASTIC 6201 2 Add the tens. 1 Add the ones. Th H T O Th H T O 11 1 27 93 +3 4 0 8 279 3 +3 4 0 8 01 1 Regroup 10 tens into Regroup 11 ones into 1 hundred 0 tens. 1 ten 1 one. 4 Add the thousands. 3 Add the hundreds. Th H TO Th H T O 1 1 1 1 11 2 7 93 2 793 +3 4 08 +3 4 0 8 2 01 6 201 Regroup 12 hundreds into © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 1 thousand 2 hundreds 2793 + 3408 = 6201 The sum of 2793 and 3408 is 6201. 26

Exercise 1 1. Add. a) Th H T O b) Th H T O 5 413 2 306 Start by adding the ones. Regroup if necessary. + 165 +7 0 4 1 c) Th H T O d) Th H T O e) Th H T O SCHOLASTIC 4 081 3 195 3 981 + 638 +6 7 6 2 +2 1 7 8 f) Th H T O g) Th H T O h) Th H T O 5 890 4 392 2 713 +1 6 1 9 +2 5 7 9 +4 3 8 7 i) Th H T O j) Th H T O k) Th H T O 7 295 1 534 5 268 +1 7 0 6 +2 4 7 9 +3 9 4 2 Practice 1 b) 6700 + 3249 = d) 363 + 8786 = 1. Find the sum. a) 132 + 3245 = f) 6253 + 2960 = c) 185 + 8794 = h) 1198 + 834 = e) 8572 + 1354 = j) 3789 + 3617 = g) 3942 + 5997 = l) 5362 + 3999 = i) 2586 + 947 = k) 3626 + 2495 = I know how to add to a 4-digit number without and with regrouping © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 27

2 Subtracting Ones, Tens, Hundreds and Thousands 2.1  Subtracting without and with regrouping a) Find the difference between 3562 and 2341. Th H T O SCHOLASTIC1 Subtract the ones.2 Subtract the tens. Th H T O Th H T O 356 2 35 62 –2 3 4 1 –2 3 4 1 1 21 3 Subtract the hundreds. 4 Subtract the thousands. Th H T O Th H T O 3 562 35 62 –2 3 4 1 –2 3 4 1 221 12 21 3562 – 2341 = 1221 The difference between 3562 and 2341 is 1221. 28 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

b) Find the difference between 4817 and 1396. Th H T O SCHOLASTIC1 Subtract the ones. 2 Regroup the hundreds and tens. Th H T O 8 hundreds 1 ten = 7 hundreds 11 tens Subtract the tens. 4817 –1 3 9 6 Th H T O 1 71 48 17 –1 3 9 6 21 3 Subtract the hundreds. 4 Subtract the thousands. Th H TO Th H TO 4 7 1 4 7 1 –1 –1 8 17 8 17 3 96 3 3 96 21 4 21 4 4817 – 1396 = 3421 The difference between 4817 and 1396 is 3421. © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 29

c) Find the difference between 4235 and 2697. Th H T O SCHOLASTIC1 Regroup the tens and ones. 2 Regroup the hundreds and tens. 3 tens 5 ones = 2 tens 15 ones 2 hundreds 2 tens = 1 hundred 12 tens Subtract the ones. Subtract the tens. Th H T O Th H T O 21 1 12 1 423 5 423 5 –2 6 9 7 –2 6 9 7 8 38 3 Regroup the thousands and hundreds. 4 Subtract the thousands. 4 thousands 1 hundred Th H T O = 3 thousands 11 hundreds Subtract the hundreds. 3 11 12 1 4 23 5 Th H T O –2 6 9 7 3 11 12 1 1 53 8 4 23 5 –2 6 9 7 53 8 4235 – 2697 = 1538 The difference between 4235 and 2697 is 1538. 30 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

d) Find the difference between 5000 and 1519. There are no Th H T O h­ undreds, tens and ones to ­subtract 9 from. SCHOLASTIC 1 Regroup the thousands, hundreds, 2 Subtract the tens. tens and ones. 5 thousands = 4 thousands Th H T O 9 hundreds 9 tens 10 ones Subtract the ones. 4 9 91 Th H T O 500 0 –1 5 1 9 4 9 91 81 500 0 –1 5 1 9 1 3 Subtract the hundreds. 4 Subtract the thousands. Th H TO Th H TO 4 9 91 4 9 91 5 0 00 5 0 00 19 19 –1 5 81 –1 5 81 4 34 5000 – 1519 = 3481 The difference between 5000 and 1519 is 3481. © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 31

Exercise 2 1. Subtract. a) Th H T O b) Th H T O 7 863 6 754 Start subtracting the ones. Regroup if necessary. – 742 –4 210 c) Th H T O d) Th H T O e) Th H T O SCHOLASTIC 7 354 4 395 8 680 – 283 –1 746 –3 978 f) Th H T O g) Th H T O h) Th H T O 7 852 9 365 4 000 –4 369 –5 478 –1 827 i) Th H T O j) Th H T O k) Th H T O 6 000 9 200 8 600 –3 279 –4 736 –3 842 Practice 2 b) 8656 – 5253 = d) 9509 – 317 = 1. Find the difference. f) 3591 – 2682 = a) 7489 – 2067 = h) 4160 – 3873 = c) 3472 – 190 = j) 1000 – 495 = e) 4183 – 375 = l) 9100 – 999 = g) 1327 – 549 = i) 4000 – 3963 = k) 6200 – 519 = 32 I know how to s ubtract from a 4-digit number without and with regrouping © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

3 Estimation 3.1  Estimating sums and differences a) Estimate the value of 523 + 608. 523 ≈ 500 Round each number to the nearest hundred, then add. 608 ≈ 600 So, 523 + 608 ≈ 500 + 600 = 1100 The value of 523 + 608 is about 1100. SCHOLASTIC b) Estimate the value of 6235 − 2169. 6235 ≈ 6200 Round each number to the nearest hundred, then subtract. 2169 ≈ 2200 So, 6235 – 2169 ≈ 6200 – 2200  = 4000 The value of 6235 − 2169 is about 4000. Exercise 3 1. Round each number to the nearest hundred to estimate the value of each of the following. a) 118 + 621 ≈ + b) 7253 + 1610 ≈ + =   = c) 485 – 103 ≈ – d)   6463 – 6257 ≈ –  =  = 3.2  Using estimation to check sums and differences a) Fin d the sum of 339 and 574. Round each number to the nearest 339 + 574 = 913 hundred, then add. Check: 339 + 574 ≈ 300 + 600 = 900 913 is about 900. The answer is reasonable. © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 33

b) Find the difference between 7213 and 1219. 7213 – 1219 = 5994 Check: 7213 – 1219 ≈ 7200 – 1200 = 6000 5994 is about 6000. The answer is reasonable. Exercise 4 SCHOLASTIC 1 . Find the sum or difference. Then, use estimation to check your answer. a) 713 + 154 = b) 4612 + 1628 = 713 + 154 ≈ + 4612 + 1628 ≈ +   = = c) 507 – 129 = d) 1936 – 1778 = 507 – 129 ≈ – 1936 – 1778 ≈ – =    = Practice 3 1. Round each number to the nearest hundred to estimate the value of each of the following. a) 832 + 770 b) 276 + 2390 c) 957 – 553 d) 1509 – 325 e) 1627 + 7721 f) 3658 + 1827 g) 6472 – 1627 h) 7364 – 7250 i) 8964 – 8219 2. Find the sum or difference. Then, use estimation to check your answer. a) 952 + 191 b) 259 + 4093 c) 643 – 534 d) 6950 – 235 e) 6213 + 1551 f) 3657 + 2837 g) 7229 – 1728 h) 9318 – 1824 i) 4739 – 2169 I know how to c heck the reasonableness of an answer e stimate an answer in addition or in addition or subtraction subtraction © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 34

4  Word Problems Mr Sharma bought a mattress for ` 3863. He also bought a blanket that cost ` 1965 less than mattress. How much did the mattress and blanket cost altogether? 1 Understand The mattress cost ` 3863. The blanket cost ` 1965 the problem. less than the mattress. I need to find the cost of the ­mattress and blanket a­ ltogether. 2 Plan what to do. Draw a bar model to solve the problem. SCHOLASTIC 3 Work out the ` 3863 Answer. mattress blanket ? ? ` 1965 ` 3863 – ` 1965 = ` 1898 The blanket costs ` 1898. ` 3863 + ` 1898 = ` 5761 The mattress and blanket cost ` 9761 altogether. 4 Check Cost of mattress and blanket – Cost of blanket if your answer = Cost of mattress ` 5761 – ` 1898 is correct.  4 16 15 11 5 7 6 – 1898 38 6 3 My answer is correct. 1 . Understand 2 . Plan 3 . Answer 4 . Check © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 35

Exercise 5 Solve the word problems. Draw bar models to help you. 1 . Understand 2 . Plan 3 . Answer 4 . Check 1. Mrs Malhotra baked 3754 chocolate chip biscuits and 2615 oat biscuits for a bake sale. How many biscuits did she bake altogether? 2. A farmer picked 2608 apples from his farm. 254 of these apples were rotten. How many of the apples picked were not rotten? 3. A bakery sold 1695 buns last week. It sold 210 more buns this week than last week. How many buns were sold altogether in both weeks? 4. Printer A can print 1374 pages in one hour. Printer A can print 128 more pages than Printer B in one hour. How many pages can both printers print altogether in one hour? SCHOLASTIC I know how to solve up to 2-step word problems involving addition and subtraction Chapter Review b) 7365 + 1231 c) 5716 + 2872 e) 1729 + 1827 f) 2637 + 2991 1. Add. h) 6253 + 1999 i) 6273 + 1987 a) 6542 + 1354 d) 1299 + 6201 c) 3562 – 2119 g) 2998 + 3449 f) 7361 – 5189 i) 6100 – 3581 2. Subtract. b) 1729 – 715 a) 7263 – 2101 e) 2913 – 1674 d) 9817 – 4109 h) 2000 – 1245 g) 8000 – 3999 36 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

3. Complete the puzzle using the difference from the given subtraction sentences. 1. 2. 3. Down ↓ Across → 4. 1. 8754 – 2568 1. 9513 – 3425 2. 9000 – 986 4. 4059 – 2555 5. 8500 – 483 5. 3. 8538 – 67 6. 7259 – 718 6. SCHOLASTIC 4. Estimate the sum or difference to the nearest hundred. Tick the answers that are correct based on your estimation. Cross out the ones that seem incorrect. a) 7612 + 1271 = 8883  b) 5341 – 449 = 4892 c) 1009 + 8217 = 9316   d) 6000 – 3351 = 2649 e) 2547 + 6154 = 8791   f) 7811 – 4949 = 2862 5. Village X has 8431 people. Village Y has 1796 fewer people than Village X. How many people are there in Village Y? 6. Rohan has 1296 marbles. Kriti has 354 more marbles than Rohan. Leena has 183 fewer marbles than Kriti. How many marbles does Leena have? 7. Fill in the missing digits. a) Th H T O b) Th H T O c) Th H T O 4 379 35 – –2 943 +4 2 9 5 2 790 02 1 5 124 8. Which of the following would have an estimated difference of 4500 to the nearest hundred? a) The difference between the greatest 4-digit number with 8 thousands and the greatest 4-digit number with 5 thousands. b) The difference between the greatest 4-digit number with 4 tens and the smallest 4-digit number with 7 thousands 2 tens. © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 37

c) The difference between the greatest 4-digit number with 6 thousands and the smallest 4-digit number with 1 thousand. d) The difference between the greatest 4-digit number with 4 hundreds and the smallest 4-digit number with 5 thousands. 9. Sam wants to add the numbers from 1 to 10. He adds them one at a time, from the left to the right. 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 1+2=3 3+3=6 6 + 4 = 10 10 + 5 = 15 . . . SCHOLASTIC Is there a faster way to add the numbers? Help Sam find a faster way to add the numbers. Show your method. Maths Lab Activity Adding numbers using an abacus Th H T O Work in groups of four. Pick 8 number cards to form two 4-digit numbers. Represent the first number on the abacus as shown. Next, add the second number to the first number using the abacus and regroup if necessary. Write the sum. Round both the numbers and find the estimated sum. Are both the actual sum and estimated sum the same? For example, First number formed = 4531 Second number formed = 2679 Sum = 4531 + 2679 = 7210 Estimated sum = 4500 + 2700 = 7200 38 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

3 Multiplication TO Let’s Revise 1. Complete the multiplication facts. 123SCHOLASTIC 1234 1 1 2 2 3 3 4 3×4= 4×3= b) 1 × 2. Fill in the missing numbers. d) 8 × a) 3 × 0 = =0 =8 c) 9 × 1 = d) 3 8 3. Find the products. ×2 a) 1 3 b) 4 3 c) 3 5 ×3 ×9 ×8 4. There are 5 stickers on each card. How many stickers are there on 28 cards? 28 × 5 = stickers on 28 cards. There are 5. A pack of 5 pencils costs ` 30. How much will 12 pencils cost? Cost of 5 pencils = ` Cost of 1 pencil = ` 30 ÷ 5 =` Cost of 12 pencils = 12 × `       = ` 12 pencils will cost ` . © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 39

1  Multiplication by 1-digit Numbers 1.1  Multiplying 3-digit numbers without regrouping Multiply 431 by 2. 431 = 4 hundreds 3 tens 1 one Hundreds Tens Ones 1 Multiply the ones by 2. Ones 431 SCHOLASTICHundredsTens ×2 431 × 2 = 862 2 1 one × 2 = 2 ones 2 Multiply the tens by 2. 431 ×2 62 3 tens × 2 = 6 tens 3 Multiply the hundreds by 2. 431 ×2 862 4 hundreds × 2 = 8 hundreds Exercise 1 b) H T O c) H T O d) H T O 443 110 1. Multiply. 202 ×4 ×2 ×8 a) H T O 320 ×3 40 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

1.2  Multiplying 3-digit numbers with regrouping Multiply 435 by 4. 435 = 4 hundreds 3 tens 5 ones Hundreds Tens Ones 1 Multiply the ones by 4. Hundreds TensSCHOLASTICOnes 2 Thousands Hundreds Tens Ones 435 ×4 435 × 4 = 1740 0 5 ones × 4 = 20 ones Regroup 20 ones into 2 tens. 2 Multiply the tens by 4. 12 435 ×4 40 3 tens × 4 = 12 tens Add the tens. 2 tens + 12 tens = 14 tens Regroup 14 tens into 1 hundred 4 tens. 3 Multiply the hundreds by 4. 12 435 ×4 1740 4 hundreds × 4 = 16 hundreds Add the hundreds. 1 hundred + 16 hundreds = 17 hundreds © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 41

Exercise 2 b) H T O c) H T O d) H T O 1. Multiply. 863 579 458 ×4 ×5 ×7 a) H T O 475 ×3 Practice 1 1. Multiply. a) 1 4 4 ×2 SCHOLASTIC b) 4 1 0 c) 9 1 1 d) 6 3 2 ×3 ×8 ×4 e) 2 8 5 f) 7 0 8 g) 5 7 8 h) 824 ×6 ×9 ×6 ×7 2. Find the products. a) 134 × 2 = b) 110 × 9 = c) 610 × 5 = d) 121 × 8 = e) 381 × 6 = f) 389 × 7 = 3. Multiply. Then, match the pot to the correct watering can. 870 × 7 541 × 8 396 × 5 958 × 9 • • • • • • • • 4328 8622 6090 1980 I know how to m ultiply 3-digit numbers by 1-digit numbers without and with regrouping 42 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

2  Multiplication of Three 1-digit Numbers 2.1  Multiplying three 1-digit numbers a) 3 × 2 × 5 Method 1 Method 2 2 × 5 = 10 3×2=6 SCHOLASTIC 3×2×5 3 × 2 × 5 = 3 × 10 =6×5 = 30 = 30 3 × 2 × 5 = 6 × 5 = 3 × 10 = 30 b) 5 × 3 × 6 Method 1 Method 2 Method 3 5×3=3×5 5×3×6 5×3×6 5×3×6 = 15 × 6 = 5 × 18 =3×5×6 = 90 = 90 = 3 × 30 = 90 The product does not get affected by how the numbers are grouped. Exercise 3 1. Show two ways to multiply 4, 6 and 5. 4×6×5 4×6×5 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 43

Practice 2 1. Match the pairs that have the same product. 8 × 7 × 3 7 × 8 × 9 8 × 9 × 6 6 × 5 × 9 •• •• 3×7×2 • • • • • • 9 × 8 × 6 8 × 7 × 9 7 × 8 × 3 7 × 3 × 2 5×6×9 2. Multiply. b) 9 × 3 × 2 e) 2 × 6 × 8 a) 2 × 7 × 5 SCHOLASTIC c) 8 × 3 × 4 d) 7 × 6 × 9 f) 7 × 8 × 5 I know how to m ultiply three 1-digit numbers 3  Multiplication by 2-digit Numbers 3.1  Multiplying numbers by 10 a) 3 × 10 b) 30 × 10 c) 300 × 10 1 10 10 100 100 1000 1 × 10 10 10 × 10 100 100 × 10 1000 1 10 10 100 100 1000 3 × 10 = 30 30 × 10 = 300 300 × 10 = 3000 1 × 10 10 10 × 10 100 100 × 10 1000 When we multiply a number by 10, we can get the product by inserting a zero at the end of the number. Exercise 4 1. Multiply. a) 5 × 10 = b)  50 × 10 = c) 500 × 10 = 44 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

2. Multiply. b) 9 × 10 = c) 12 × 10 = e) 302 × 10 = f) 870 × 10 = a) 4 × 10 = d) 60 × 10 = 3.2  Multiplying 2-digit numbers by tens Multiply 21 by 30. Method 1 SCHOLASTIC10 1× 10 100 10 ×3 100 100 100 10 10 10 10 100 100 100 100 21 630 210 30 = 10 × 3 21 × 30 = 21 × 10 × 3 = 210 × 3 = 630 Method 2 10 1 ×3 10 10 10 1 1 1 × 10 100 100 100 10 10 10 10 10 10 10 100 100 100 63 21 630 21 × 30 = 21 × 3 × 10 30 = 3 × 10 = 63 × 10 = 630 Method 3 1 Multiply 21 by 2 Multiply 1 one by 3 Multiply 2 tens by 0 ones. 3 tens. 3 tens. 21 × 30 21 21 0 × 30 × 30 21 × 30 = 630 30 630 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 45

Exercise 5 1. Multiply. a) 56 × 40 = 56 × × 56 × × 40 = 67 = × 30 × b) 67 × 30 = 67 × × 82   = × 30 SCHOLASTIC   = 92 × × 50 c) 82 × 30 = 82 × ×    =   = × d) 92 × 50 = 92 × ×    =   = 3.3  Multiplying 2-digit numbers by 2-digit numbers Multiply 43 by 26. 2 Multiply 43 by 20. 3 Add. 1 Multiply 43 by 6. 14 3 1 1 × 26 43 43 258 × 26 × 26 258 2 5 8 ← 43 × 6 860 8 6 0 ← 43 × 20 43 × 26 = 1118 1 1 1 8 ← 43 × 26 46 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

Exercise 6 1. Multiply. a) 3 6 b) 5 0 c) 67 × 12 × 29 × 43 ← 36 × 2 ← 50 × 9 ← 67 × 3 ← 36 × 10 ← 50 × 20 ← 67 × 40 ← 36 × 12 ← 50 × 29 ← 67 × 43 d) 8 3 e) 5 7 f)SCHOLASTIC 85 × 24 × 27 × 31 ← 85 × 4 ← 83 × 7 ← 57 × 1 ← 85 × 20 ← 83 × 20 ← 57 × 30 ← 85 × 24 ← 83 × 27 ← 57 × 31 Practice 3 1. Multiply. a) 60 × 10 b)  87 × 10 c) 99 × 10 d)  59 × 10 e)  510 × 10 f) 765 × 10 g) 930 × 10 h)  905 × 10 i) 807 × 10 2. Multiply. a) 29 × 70 b) 79 × 60 c) 60 × 30 d) 23 × 30 e) 85 × 40 f) 68 × 50 g) 57 × 50 h) 46 × 20 i) 99 × 80 3. Find the products. a) 53 × 22 b) 81 × 37 c) 18 × 49 d) 90 × 51 e) 12 × 25 f) 83 × 58 g) 86 × 69 h) 78 × 42 i) 85 × 32 I know how to multiply up to 3-digit numbers by 10 multiply 2-digit numbers by tens multiply 2-digit numbers by 2-digit numbers © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 47

4  Word Problems There are 19 classes in a school with 32 students in each class. If 410 of the students are boys, how many girls are there? 1 Understand There are 19 classes. There are 32 students in each the problem. class. There are 410 boys in all. I have to find the number of girls. SCHOLASTIC2 Plan Draw bar models to solve the problem. what to do. 3 Work out the 32 Answer. 1234 18 19 ? 19 × 32 = 608 There are 608 students in the school. 608 410 ? 608 – 410 = 198 There are 198 girls. 4 Check 19 × 32 ≈ 20 × 30 if your answer = 600 is reasonable. 410 ≈ 400 600 – 400 = 200 198 is about 200. My answer is reasonable. 1 . Understand 2 . Plan 3 . Answer 4 . Check 48 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

Exercise 7 Solve the word problems. Draw bar models to help you. 1 . Understand 2 . Plan 3 . Answer 4 . Check 1. Kavya bought 18 boxes of tarts. There are 65 tarts in each box. How many tarts did she buy altogether? 2. Mohan delivers 65 copies of a newspaper every day. How many copies does he deliver in 30 days? 3. Kim wants to get 1200 blankets for a charity drive. She bought 105 sets of blankets. There are 8 blankets in a set. How many more blankets does she need to get? 4. Chef Karan bakes 11 cakes in a day. If he bakes for 20 days in each month, how many cakes will Chef Karan bake in 2 months? SCHOLASTIC I know how to solve up to 2-step word problems involving multiplication Chapter Review 1. Fill in the missing numbers. a)  110 × 10 = b)  405 × = 4050 d)  100 × = 1000 c) × 10 = 700 f)  129 × = 1290 e) × 10 = 2050 2. Multiply. a) 7 tens 1 one 5 hundreds by the greatest 1-digit even n­ umber b) 4 tens 3 hundreds 0 ones by the product of 2 and 3 c) 6 hundreds 2 ones 3 tens by the greatest 1-digit odd number d) 5 hundreds 8 ones by the product of 2 and 4 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 49

3. Multiply. a) 132 × 3 b) 432 × 6 c) 729 × 4 d) 60 × 47 e) 90 × 98 f) 86 × 68 g) 74 × 74 h) 99 × 91 4. A pencil case costs `93. A school bag costs 13 times as much as the pencil case. a)  How much does the school bag cost? b)  H ow much more does the school bag cost than the pencil case? 5. There are 476 red paper clips and 462 blue paper clips in a box. How many paper clips are there in 7 such boxes? SCHOLASTIC 6. Ramit has 501 stamps. Ramit’s brother has 3 times the stamps Ramit has. How many stamps do Ramit and his brother have altogether? 7. The product of two of the numbers given below is 1500. Which are the two numbers? 30 15 50 75 8.  × 8 = 32  ×  × › = 80  ›What numbers do and stand for? 9. There are 30 crayon boxes. 12 boxes have 12 crayons each and the remaining boxes have 18 crayons each. Explain to your friend how you can find the total number of crayons. Maths Lab Activity Multiplying 2-digit numbers Work in pairs. 5 42 3 Each pair picks 4 number cards. Each student in the pair will form two 2-digit numbers using the cards. The students will multiply both the numbers formed. Then, compare the products. For example, one pair picks number cards, 5, 4, 2 and 3. Student 1: 54 × 23 = 1242 Student 2: 45 × 32 = 1440 1440 is greater than 1242. 50 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

4 Division TO Let’s Revise 1. Draw circles to make pairs. Fill in the blank with even or odd. SCHOLASTIC There is an number of balloons. 2. Divide. b) 5 ÷ 5 = c) 0 ÷ 3 = a) 8 ÷ 1 = 3. Divide using long division. b) 21 ÷ 3 a) 18 ÷ 2 d) 24 ÷ 6 c) 30 ÷ 5 4. Rachel has 30 beads. She wants to make 3 bracelets. If each bracelet has the same number of beads, how many beads are there in each bracelet? 30 ? 5. Amy bought 40 apples. She packed them into baskets of 4 apples each. How many baskets of apples were there? 40 12 ? 4 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0 51

1  Quotient and Remainder 1.1  Dividing with remainder 16 carrots are shared equally among 3 rabbits. SCHOLASTIC Each rabbit gets 5 carrots. 1 carrot is left over. This can be written as: 16 ÷ 3 = 5 R1 We use R for remainder. Quotient Remainder 5 3 16 1 5 ← 3 × 5 = 15 1 ← 16 – 15 = 1 The answer that we get when we divide a number by another number is called the quotient. The number left over is called the remainder. 52 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

Exercise 1 1. Divide 11 cards equally into 2 groups. Number of cards per group = Number of cards left over = SCHOLASTIC 11 ÷ 2 = R 2. Divide. a) 35 ÷ 5 b) 26 ÷ 4 Quotient = Quotient = Remainder = Remainder = 1.2  Even and odd numbers a) Divide 12 sticks into 2 equal groups. 12 ÷ 2 = 6 6 There are 6 sticks in each group. 12 is an even number. 2 12 1 2 ← 2 × 6 = 12 b) Divide 15 sticks into 2 equal groups. 0 ← 12 - 12 = 0 15 ÷ 2 = 7 R1 7 There are 7 sticks in each group. 1 stick is left over. 15 is an odd number. 2 15 1 4 ← 2 × 7 = 14 1 ← remainder 1 one When even numbers are divided by 2, the remainder is always 0. 53 When odd numbers are divided by 2, the remainder is always 1. © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0

Exercise 2 1. Divide the tomatoes into 2 groups. Then, fill in the blanks. There is a remainder of . Draw circles to show the tomatoes as 2 equal 13 is an number. groups. An even number has no ­remainder when divided by 2. An odd number has a r­emainder of 1 when divided by 2. SCHOLASTIC 2. Divide. Then, fill in the blanks with even or odd. a) 2 1 8 b) 2 1 1 18 is an number. 11 is an number. Practice 1 1. Fill in the missing numbers. a) 12 ÷ 4 = R b) 17 ÷ 3 = R quotient = quotient = remainder = remainder = 2. Divide. Then, write if the quotient is even or odd. a) 14 ÷ 2 b) 19 ÷ 2 c) 16 ÷ 2 d) 10 ÷ 2 e) 20 ÷ 2 f) 17 ÷ 2 I know how to identify even and odd numbers using d ivide 2-digit numbers with remainder division 54 © 2019 Scholastic Education International (S) Pte Ltd ISBN 978-93-52750-16-0