WMPB16034A

Special Features

3 Topical-based practices 3 Revision papers and Semestral assessment

3 Use of calculators 3 Complete answers

Mastering Mathematics Workbook 6A

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

Latest

MOE Syllabus

Primary

www.PelangiBooks.com • Online Bookstore • Online Library •

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 )

WMPB16034A

ISBN 978-981-07-1234-1

,!7IJ8B0-hbcdeb!

In collaboration with Dickens Publishing Ltd. (UK)

Lilian Yeo

Unit 1

Algebra ............................................................ 1

Unit 2

Angles ............................................................13

General Revision 1 ......................................................... 25 Unit 3

Identifying Solids and Nets ..................................31

Unit 4

Fractions ........................................................ 34

General Revision 2.......................................................... 40 Unit 5

Ratio ............................................................. 47

Unit 6

Percentage ..................................................... 55

General Revision 3 ......................................................... 66 Semestral Assessment .....................................................71 Answers .................................................................... 87

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Mathematics Primary 6A Unit 1 Algebra

1

Algebra

A Write an algebraic expression for each of the following. 1. Mrs Wong bought 12 doughnuts. Her children ate x doughnuts. How many doughnuts were uneaten?

2. Amy received $y from her mother. Amy’s father gave her thrice as much as her mother. How much did Amy receive in total?

3. Mabel brought m pieces of cake to school. She shared them equally with her 5 friends. How many pieces of cake did Mabel receive?

4. Karen is n years old. Her mother is three times as old as her. Karen’s father is 5 years older than her mother. What is the average of their ages?

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Mathematics Primary 6A Unit 1 Algebra

5. Kelly had p erasers. She gave 2 erasers to Carmen and 5 erasers to John. How many erasers does Kelly have now?

6. Matthew is now q years old. Steven is 2 years younger than him. What is the sum of their ages in 3 years’ time?

7. A bag cost $r and a file cost $t. Mr Tham bought 6 bags and 5 files. How much did he pay in total?

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Mathematics Primary 6Aâ&#x20AC;&#x192; Unit 1â&#x20AC;&#x201A;Algebra

8. Roger bought x ml of milk. He drank 300 ml of milk every day. How much milk was left after a week?

9. Sally bought a skirt for $x and two blouses which cost $3x each. After paying for her purchase, she had $21 left. How much did she have at first?

10. A publisher printed 1500 copies of bakery books. Seven distributors bought k copies each. 52 copies were defective and had to be disposed. Find the remaining number of copies of the bakery books.

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Mathematics Primary 6A Unit 1 Algebra

B Write an algebraic expression for each of the following. 1. Add 8 to p 2. Subtract q from 20 3. 15 more than r 4. s less than 79 5. Multiply 6 by t 6. Divide u by 3

C Find the value of the following algebraic expressions. 1. 3 + a, when a = 8 2. b + 7, when b = 12 3. 2e + 5e, when e = 6 4. 6f – 3f, when f = 2 5. 8 + 3m, when m = 7

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Mathematics Primary 6A Unit 1 Algebra

6. 7j – 12, when j = 3 7. 14d, when d = 3 8. h × 2h, when h = 5 9.

c , when c = 24 6

10 5g ÷ 4, when g = 8 11. 120k ÷ 3, when k = 4 12.

16q + 100 , when q = 20 70

13. 5n – 4 , when n = 8 9 14.

12r + 98, when r = 11 6

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Mathematics Primary 6A Unit 1 Algebra

D Write your answers on the lines provided. 1. 4a +

= 15a

2. 25m –

3. 7x + 3x –

4. 10 × b = 5 ×

= 9m

= 2x

5. Find the value of 12p – 6, when p = 5.

6. Jenny was paid $y dollars for a week’s work. She worked five days in a week. How much was she paid for each day?

7. The length of a rectangle is 5r cm and the breadth is 2r cm. Write an algebraic expression for the perimeter of the rectangle.

8. The temperature in the morning was t °C. It had risen 3°C by midday and then it fell 1°C by sunset. What was the temperature at sunset?

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Mathematics Primary 6A Unit 1 Algebra

9. Square A has a length of 2q and Square B has a length of 7r. Square A is bigger than Square B. Write an algebraic expression for the difference in perimeter between the two squares.

10. Subtract 3x from the product of 10x and 8.

11. w books are shared equally among 18 children. How many books will each child receive?

12. A blouse costs $t and a skirt costs $2 less. How much would three blouses and two skirts cost?

13. Peggy is k years old. Her mother is twice as old as she. What is the sum of their ages in 5 years’ time?

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Mathematics Primary 6A Unit 1 Algebra

E Simplify the following algebraic expressions. 1. p + p =

2. q + 2q =

3. 4a + 2a + 10a =

4. r – r =

5. 4s – 2s =

6. 10d – 7d – d =

7. 12h + 9h + 3 =

8. 5 + 3b + 2b + 24 =

9. 32f – f + 20f =

10. 40g – 12 – 29g =

11. 12 + 4d – 9 – 2d =

12. 26 + 8e – 13 – 5e =

13. 1 + 6b + 9 – 5b =

14. 8m – m + 6 – 2m =

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Mathematics Primary 6Aâ&#x20AC;&#x192; Unit 1â&#x20AC;&#x201A;Algebra

F Solve the following word problems. 1. Box A contains 100 paper clips. Box B has k paper clips more than Box A. (a) How many paper clips must be moved from Box B to Box A so that both boxes have an equal number of paper clips? (b) If k = 60, find the total number of paper clips in Box A and Box B.

2. The utility company charges $a per kWh for the first 500 kWh of electricity used and $2a for every subsequent kWh of electricity used. How much does Alan have to pay for using 922 kWh of electricity? Express your answer in terms of a.

3. The number of pupils in Class A, Class B and Class C are in the ratio 5 : 7 : 4. Class B has 84n pupils. (a) How many pupils are there in Class A? Give your answer in terms of n. (b) Find the total number of pupils in three classes in terms of n.

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Mathematics Primary 6Aâ&#x20AC;&#x192; Unit 1â&#x20AC;&#x201A;Algebra

4. Cindy bought 6 packs of orange juice for a party. Each pack cost $p and contained 8 cartons of orange juice. (a) How much did each carton of orange juice cost in terms of p? (b) If p = 24, how much did Cindy pay in total?

5. Julian spent $210 on a pair of sports shoes and $t on a jersey. (a) How much did Julian have at first? Express your answer in terms of t. (b) If t = 38, how much money did Julian spend?

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Mathematics Primary 6A Unit 1 Algebra

6. At a kiosk, a packet of chips costs $c. A packet of cheese costs $6. A box of chocolate costs 3 times as much as the chips. (a) Find the total cost of 3 packets of chips and 2 packets of cheese. Express your answer in terms of c. (b) If c = 2, what is the total cost of 2 packets of chips, 3 packets of cheese and 2 boxes of chocolates?

7. At Cinema Q, the price of a popcorn set is $e. A child’s ticket for a movie costs $8 and the adult’s ticket costs 4 times as much as a popcorn set. (a) Find the total cost of 2 child tickets and 3 popcorn sets. Give your answer in terms of e. (b) Mr and Mrs Lee take their 3 children for a movie and buy 2 popcorn sets. If e = 4, how much do they spend in total?

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Mathematics Primary 6Aâ&#x20AC;&#x192; Unit 1â&#x20AC;&#x201A;Algebra

8. Jack is 8 years old. Jim is thrice as old as Jack. Jeremy is x years younger than Jim. (a) How old is Jeremy? Give your answer in terms of x. (b) If x is 5, how much elder is Jeremy than Jack?

9. Mary earns $2100 every month. Mandy earns 2 as much as Mary. Wendy 3 earns $f more than Mandy. (a) How much does Wendy earn every month? Give your answer in terms of f. (b) If f = 300, how much do three of them earn in total?

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Mathematics Primary 6A Unit 2 Angles

2

Angles

A Find the unknown angles. The following figures are not drawn to scale. 1. a

40°

∠a =

2. b

∠b =

125°

3. c 85°

95°

∠c =

120°

4.

∠d =

d e

O

56°

∠e =

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Mathematics Primary 6A Unit 2 Angles

B Find the unknown angles. The following figures are not drawn to scale. 1.

p

60°

70°

∠p =

2. q

∠q =

54°

3. r

∠r =

4. s

35°

∠s =

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Mathematics Primary 6A Unit 2 Angles

C Find the unknown angles. The following figures are not drawn to scale. 1.

B

A 65°

∠ADC = ∠BAD = D

2.

C

E

F 117°

∠FGH = ∠EHG =

H

3.

G

I

J

∠JIL = ∠JIL + ∠JKL =

135° L

K

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