Thinking Cap 3 by Pelangi Publishing

Whole Numbers (Addition and Subtraction)

1 otes

Thousands

Hundreds

Tens

Ones

stands for 6 tens or 60

stands for 5 ones or 5

stands for 2 stands for 3 thousands hundreds or 2000 or 300

2365 = 2 thousands 3 hundreds 6 tens 5 ones 2365 = 2000 + 300 + 60 + 5

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ÂŠ Pelangi Publishing Singapore Pte. Ltd.

9/6/13 11:01 AM

Mathematics Primary 3 Unit 1 Whole Numbers (Addition and Subtraction)

xample 1 Mable collected 306 stamps while Cassie collected 258 stamps. Patrick collected 15 fewer stamps than the total number of stamps collected by Mable and Cassie. How many stamps did they collect altogether?

olution Mable

306 ?

Cassie

258

1 3 0 6 + 2 5 8 5 6 4

306 + 258 = 564 Mable and Cassie collected 564 stamps.

Mable and Cassie

564 ?

Patrick

564 – 15 = 549 Patrick collected 549 stamps.

564 + 549 = 1113 They collected 1113 stamps altogether.

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5 14 5 6 4 – 1 5 5 4 9 1 1 5 6 4 + 5 4 9 1 1 1 3

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Mathematics Primary 3 Unit 1 Whole Numbers (Addition and Subtraction)

xample 2 Rachel and Peter have read 435 books altogether. Rachel has read 35 more books than Peter. How many books has Rachel read?

olution ? Rachel 35

Peter

435

1 unit

1 unit + 1 unit 2 units 2 units 1 unit

= = = = =

2 units 435 – 35 400 200 + 200 200

4 3 5 – 3 5

4 0 0

Peter has read 200 books.

200 + 35 = 235

2 0 0 + 3 5

2 3 5

Rachel has read 235 books.

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Mathematics Primary 3 Unit 1 Whole Numbers (Addition and Subtraction)

ractice Solve the following word problems. 1. Andrea has 286 blue paper clips. She has 98 fewer green paper clips than blue paper clips. How many paper clips does Andrea have altogether?

2. There are 243 pots of rose plants in a botanic garden. The number of pots of orchid plants is 84 more than the number of pots of rose plants. How many pots of plants are there in the botanic garden?

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Mathematics Primary 3 Unit 1 Whole Numbers (Addition and Subtraction)

3. Jacob has 215 more bottle caps than Gary. If Jacob has 428 bottle caps, how many bottle caps do both of them have altogether?

4. Mr Sanders has 539 newspapers to deliver in a day. He delivers 286 newspapers to Household A, some newspapers to Household B and has 125 newspapers left. How many newspapers does he deliver to Household B?

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Mathematics Primary 3 Unit 1 Whole Numbers (Addition and Subtraction)

5. A computer costs $203 more than a handphone. If a handphone costs $718, what is the total cost of both items?

6. Joe spent $142 more than Susan during a trip. Austin spent $84 less than Susan. How much more money did Joe spend than Austin?

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Mathematics Primary 3 Unit 1 Whole Numbers (Addition and Subtraction)

7. There are 1354 T-shirts at the factory outlet. 716 of them are blue and the rest are red. How many more blue T-shirts than red T-shirts are there at the factory outlet?

8. Samuel had 568 sheets of paper. He received another 1208 sheets of paper from John and gave Chris 612 sheets of paper. How many sheets of paper did Samuel have left?

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Mathematics Primary 3 Unit 1 Whole Numbers (Addition and Subtraction)

9. Uncle Tom baked 1800 pieces of cookies. He gave 254 cookies to Andrew and gave Mike 123 more cookies than Andrew. He then kept 615 cookies for himself and gave the remaining to Eli. How many cookies did Eli receive?

10. Alex scored a total of 1084 points in a game after two trials. If he scored 694 points in the first trial, find the difference between the points of his two trials.

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Mathematics Primary 3 Unit 1 Whole Numbers (Addition and Subtraction)

11. Danny and Michelle sold 568 glasses of lemonade in a charity fair. Michelle sold 54 more glasses of lemonade than Danny. How many glasses of lemonade did Danny sell?

12. Jeriel collected 54 more empty cans than Stephenie. Stephenie collected 12 more empty cans than Suzie. If Jeriel collected 294 empty cans, how many empty cans did three of them collect altogether?

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Whole Numbers (Multiplication and Division)

2 otes

Multiplication table of 6 to 9. ×

xample 1 The table shows the price of some stationery. Dorothy bought 4 notepads and 2 storybooks. How much did she pay?

Item

Price per unit ($)

Notepad

Storybook

olution Notepads

$6 ?

Storybooks

4 × $6 = $24 The total price of 4 notepads is $24.

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4 × $ 6 $ 2 4

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Mathematics Primary 3 Unit 2 Whole Numbers (Multiplication and Division)

2 × $ 9 $ 1 8

2 × $9 = $18 The total price of 2 storybooks is $18.

$ 2 4 + $ 1 8 $ 4 2

$24 + $18 = $42 Dorothy paid $42 in total.

xample 2 The number of female pupils in the school hall is 3 times as many as the male pupils. If there are 136 more female pupils than male pupils, find the total number of female pupils in the school hall.

olution 1 unit Male pupils

Female pupils 136 ?

2 units = 136 1 unit = 136 ÷ 2 = 68 The number of male pupils is 68. Female pupils = 3 units 3 units = 3 × 68 = 204 The total number of female pupils is 204 .

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6 8 2 1 3 6 1 2 1 6 1 6 0

6 8 × 3 2 0 4

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Mathematics Primary 3 Unit 2 Whole Numbers (Multiplication and Division)

ractice Solve the following word problems. 1. Mrs Tang bought 28 kg of potatoes. Mrs Chong bought 4 times as many potatoes as Mrs Tang bought. How many kilograms of potatoes did they buy altogether?

2. Mark is 10 years older than Philip. If Mark is 6 times as old as Philip, how old is Mark?

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Mathematics Primary 3 Unit 2 Whole Numbers (Multiplication and Division)

3. The total number of pupils in Primary 3 is 216. There are 5 times as many girls as boys. How many girls are there in Primary 3?

4. The price of a digital camera is 4 times the price of a pair of headphones. If a digital camera costs $816, how much do 8 pairs of headphones cost?

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Mathematics Primary 3 Unit 2 Whole Numbers (Multiplication and Division)

5. Mrs Brown bought 3 similar boxes of highlighters to distribute among 6 pupils. She gave 18 highlighters to each pupil and had 12 highlighters left. How many highlighters were there in each box at first?

6. Winnie bought 6 large packets of gummy bears which contained 64 gummy bears each. She then distributed the gummy bears equally among 35 children. If each child received 8 gummy bears, how many gummy bears did she have left?

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Mathematics Primary 3 Unit 2 Whole Numbers (Multiplication and Division)

7. Mr Bob gave 7 cards to each of his 32 pupils. He had 11 cards left. How many cards did Mr Bob have at first?

8. Classroom A had 193 chairs while Classroom B had 83 chairs. Some chairs were moved to Classroom A for the Children’s Day party. The number of chairs in Classroom A became 5 times as many as the number of chairs in Classroom B. How many chairs were moved from Classroom B to Classroom A?

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