Mastering Mathematics 5A

WMPB15034A

Special Features

3 Topical-based practices 3 Revision papers and Semestral assessment

3 Challenging questions 3 Complete answers

Mastering Mathematics Workbook 5A

Mastering Mathematics is a comprehensive series of assessment workbooks which is written based on the latest Primary Mathematics Syllabus issued by the Ministry of Education of Singapore. Each of the workbooks provides sufficient practices on various types of questions. The approach adopted by the writers aims at reinforcing mastery of mathematical concepts, improving problem-solving skills and developing creative and critical thinking skills.

PELANGI

Topic-By-Topic

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MOE Syllabus

Primary

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Published by:

Pelangi Publishing Singapore Pte. Ltd. In collaboration with:

Dickens Publishing Ltd. Suite G7-G8, Davina House, 137-149 Goswell Road, London, EC1V 7ET, United Kingdom.

E-mail: info@dickenspublishing.co.uk

( 201112597 C )

WMPB15034A

ISBN: 978-981-07-1232-7

,!7IJ8B0-hbcdch!

In collaboration with Dickens Publishing Ltd. (UK)

Lilian Yeo

Unit 1

Whole Numbers (Part 1)................................................ 1

Unit 2 Whole Numbers (Part 2)............................................... 7 General Revision 1................................................................ 17 Unit 3 Fractions (Part 1)....................................................... 22 Unit 4 Fractions (Part 2)...................................................... 31 General Revision 2............................................................... 37 Unit 5 Area of Triangles...................................................... 43 Unit 6 Ratio..................................................................... 49 General Revision 3............................................................... 58 Semestral Assessment.......................................................... 64 Calculator Skills................................................................... 79 Answers........................................................................... 81 iv

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Mathematics Primary 5A Unit 1 Whole Numbers (Part 1)

1

Whole Numbers (Part 1)

A Write the numbers in words.

1. 357 432 2. 673 591 3. 2 135 468 4. 6 500 624 5. 7 924 780 6. 8 926 177

B Write the numbers in numerals.

1. Two hundred thousand, three hundred and seventy-four 2. Six hundred and twenty-one thousand 3. Three million, five hundred and sixty 4. Five million, seven hundred and twenty-eight thousand, one hundred and thirty-one 5. Eight million, seven hundred and thirty-six thousand, one hundred and twelve 6. Nine million, one hundred and twenty-nine thousand, seven hundred and twenty-nine

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Mathematics Primary 5A Unit 1 Whole Numbers (Part 1)

C Fill in the blanks.

1. In 37 928, (a) the digit 3 stands for (b) the digit 7 is in the

. place.

(c) the value of the 9 digit is

.

2. In 81 746, (a) the digit 7 stands for (b) the digit 4 is in the

. place.

(c) the value of the digit 8 is

.

3. In 521 789, (a) the digit 5 stands for (b) the digit

. is in the ten thousands place.

(c) the value of the digit 8 is

.

4. In 7 310 856, (a) the digit 7 stands for (b) the digit (c) the digit 6 stands for 5. 83 725 = 80 000 +

. is in the hundred thousands place. . + 700 + 25

6. 472 900 = 470 000 + 2000 + 7. 2 145 000 = 2 000 000 + 8. 3 003 030 =

+ 5000 + 3000 + 30

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Mathematics Primary 5A Unit 1 Whole Numbers (Part 1)

D Circle the smallest number.

1. 453 872

,

435 297

,

435 987

2. 385 286

,

388 826

,

358 652

3. 9 340 000

,

9 304 100

,

9 430 010

E Circle the greatest number.

1. 672 145

,

665 251

,

692 154

2. 521 379

,

512 973

,

521 739

3. 8 617 001

,

8 167 000

,

8 618 023

F Arrange the following numbers ‌ 1. in increasing order.

45 732, 43 574, 43 457, 42 987

2. in ascending order.

76 124, 73 568, 78 953, 76 214

3. in order, beginning with the smallest.

132 917, 152 871, 122 851, 112 917

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Mathematics Primary 5A Unit 1 Whole Numbers (Part 1)

4. in decreasing order.

2 113 758, 2 313 578, 2 318 687, 2 112 578

5. in descending order.

81 736, 87 163, 85 713, 81 926

6. in order, beginning with the greatest.

514 689, 535 921, 509 862, 519 846

G Complete each number pattern below.

1. 32 126, 32 146,

, 32 186,

2. 69 817, 68 817,

, 66 817,

3. 256 770, 266 770,

,

, 296 770

4. 8 850 200,

, 8 650 200, 8 550 200,

5. 4 010 755,

, 6 030 775, 7 040 785,

H Round off the numbers below to the nearest thousand. 

2. 7580

3. 37 345 

4. 492 499 

5. 574 589 

6. 789 855 

7. 321 001 

8. 500 500 

1. 2492



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Mathematics Primary 5A Unit 1 Whole Numbers (Part 1)

I Round off the numbers to the nearest thousand. Then estimate the values.

1. 3158 + 5283 

2. 5510 – 1890 

3. 47 459 + 33 518 

4. 26 851 – 17 152 

5. 8915 – 2912 – 4125 

6. 8105 + 8011 + 1105 

7. 389 910 + 97 179 + 8811 

8. 781 498 – 32 485 – 113 561 

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Mathematics Primary 5A Unit 1 Whole Numbers (Part 1)

J Round off the 4-digit numbers to the nearest thousand. Then estimate the values.

1. 3390 × 4 

2. 8502 × 5 

3. 5035 × 7 

4. 6993 × 6 

5. 1816 ÷ 5 

6. 6009 ÷ 3 

7. 3991 ÷ 8 

8. 8663 ÷ 9 

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Mathematics Primary 5A Unit 2 Whole Numbers (Part 2)

2

Whole Numbers (Part 2)

A Use a calculator to work out each of the following.

1. 15 127 + 489 = 3. 87 × 94 =

4. 2134 ÷ 11 =

5. 16 243 – 9587 – 267 = 7. 35 867 × 12 =

2. 28 161 – 5879 =

6. 46 539 + 3482 + 332 051 =

8. 90 882 ÷ 54 =

B Write the correct answers on the lines provided.

1. Find the difference between $52 071 and $18 793.

2. Find the sum of 723 l and 189 l.

3. Find the quotient of 11 330 g and 11.

4. Find the product of 2382 kg and 14.

5. Find the sum of 41 138 km and 18 246 km.

6. Find the difference between 32 110 kg and 8457 kg.

7. Find the product of 1432 l and 15.

8. Find the quotient of 77 742 g and 63.

9. Find the product of $18 125 and 12.

10. Find the quotient of 15 048 kg and 99.

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Mathematics Primary 5A Unit 2 Whole Numbers (Part 2)

C Multiply the following.

1. 77 × 10 =

2. 3250 × 10 =

3. 2547 × 10 =

4. 28 × 100 =

5. 739 × 100 =

6. 1819 × 100 =

7. 56 × 1000 =

8. 348 × 1000 =

9. 2649 × 1000 =

10. 900 × 1000 =

11. 8000 × 1000 =

12. 10 000 × 1000 =

D Fill in the blanks.

1. 21 × 40 = 21 ×

tens =

2. 309 × 80 = 309 ×

tens =

tens =

3. 1503 × 50 = 1503 ×

tens =

tens =

4. 32 × 300 = 32 ×

tens =

hundreds =

5. 627 × 5000 = 627 ×

hundreds =

thousands =

6. 7483 × 600 = 7483 ×

thousands =

hundreds =

hundreds =

E Divide the following numbers.

1. 80 ÷ 10 = 3. 7770 ÷ 10 =

2. 590 ÷ 10 =

5. 22 300 ÷ 100 =

4. 3200 ÷ 100 =

7. 70 000 ÷ 1000 = 9. 480 ÷ 40 = 11. 64 000 ÷ 800 = 13. 84 000 ÷ 7000 = 15. 122 000 ÷ 2000 =

6. 900 ÷ 100 =

8. 249 000 ÷ 1000 = 10. 16 560 ÷ 90 =

12. 600 000 ÷ 5000 =

14. 105 000 ÷ 3000 = 16. 720 000 ÷ 9000 =

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Mathematics Primary 5A Unit 2 Whole Numbers (Part 2)

F Estimate the values of the following. Then use a calculator to find the actual answers. Is the actual answer reasonable or unreasonable? Circle your choice.

1. 2140 × 19 

2. 7920 × 31 

Using calculator, 2140 × 19 =

Using calculator, 7920 × 31 =

(Reasonable, Unreasonable)

(Reasonable, Unreasonable)

. 19 548 ÷ 54 3 

. 8106 ÷ 42 4 

Using calculator, 19 548 ÷ 54 =

Using calculator, 8106 ÷ 42 =

(Reasonable, Unreasonable)

(Reasonable, Unreasonable)

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Mathematics Primary 5A Unit 2 Whole Numbers (Part 2)

G Find the values of the following. Then check your answers using a calculator.

1. (45 + 22 + 23) ÷ 9 =

2. (24 ÷ 6) + 26 – 10 =

3. 57 – (81 ÷ 9) + (15 × 6) =

4. 63 ÷ (249 – 240) × 50 =

5. 9 × (27 + 3) – 40 =

6. (8 × 6) ÷ 4 + 30 =

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Mathematics Primary 5A Unit 2 Whole Numbers (Part 2)

7. 64 ÷ 8 + 12 × (55 – 15) =

8. 500 + (91 – 41) ÷ 5 × 20 =

9. 200 ÷ 40 × (17 + 3) =

10. 56 ÷ (14 – 7) – 5 + (9 × 3) =

11. (25 – 5) × 6 + (36 – 12) ÷ 4 =

12. 81 ÷ (38 – 29) + (7 × 4) =

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Mathematics Primary 5A Unit 2 Whole Numbers (Part 2)

H Solve the following word problems.

1. There are 10 cans of paint in a carton. Each can of paint costs $14. Find the total cost of 3 cartons of paint.

2. Arthur has 20 each of Box A and Box B. Each Box A has a mass of 9 kg. Each Box B has a mass of 6 kg more than Box A. Find the total mass of the boxes.

3. A trader earned $328 on Wednesday. He earned $43 more on Wednesday than on Tuesday. The money that he earned on Thursday was twice the amount he earned on Wednesday. How much money did the trader earn altogether on these three days?

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Mathematics Primary 5A Unit 2 Whole Numbers (Part 2)

4. Jill has four times as much money as John. After giving John $500, Jill has twice as much money as John. (a) How much money does John have in the end? (b) How much money does Jill have at first?

5. Dan bought 4 shorts at $32 each, 3 shirts at $41 each and a few caps at $14 each. He paid a total of $335 for all the items. How many caps did Dan buy?

6. Rosy bought a new laptop. She made an initial payment of $559. The rest of the amount was paid in monthly instalments of $115 over 2 years. Find the price of the laptop.

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Mathematics Primary 5A Unit 2 Whole Numbers (Part 2)

7. Bill kept 960 marbles in some boxes. There were 12 marbles in each box. He gave away 12 boxes of marbles to his friends and repacked the rest into packets of 16 each. How many packets of marbles did he have in the end?

8. Cindy had less money than Patrick. They had $752 altogether. After Patrick spent $140 and Cindy received $188 from her mother, each of them had the same amount of money. How much did Cindy have at first?

9. There are 24 bottles of milk in a carton. Each bottle contains 500 ml of milk.

What is the total volume of 30 cartons of milk? Give your answer in litres.

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Mathematics Primary 5A Unit 2 Whole Numbers (Part 2)

10. A survey found that 100 pupils had $12 pocket money and 50 pupils had $15 pocket money for their daily expenses. Find the average amount of pocket money of each pupil.

11. A gold concert ticket costs $250, a silver concert ticket costs $200 and a bronze concert ticket costs $160. The organiser sold 200 gold tickets, 150 silver tickets and some bronze tickets. The total amount collected for the concert was $99 200. How many bronze tickets were sold?

12. There are 5 times as many boys as girls in a group. If there are 80 more boys than girls, how many pupils are there altogether in the group?

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