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978-1-316-61134-0 — Cambridge Mental Maths Grade 4

Zonia Jooste
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Mental Maths Workbook • Grade 4 TERM 1 • WEEK 1

Term 1
When you work with multiple-choice questions, you only need to circle the letter
next to the correct answer.

Activity 1 Count and compare numbers

Content Area 1: Numbers, operations and relationships
Topic 1.1: Whole numbers

Work with the class.

1. How many counters are in each group? Count aloud in your groups.
a) b)

___________ ___________
c) d)

We use the ___________ ___________

relation signs 2. Fill in the relation sign <, > or = to make each statement correct.
<, > and =
to compare a) 1 880 ____ 1 808 b) 4 404 ____ 4 440
numbers. c) 9 872 ____ 9 782 d) 5 055 ____ 5 500

Work on your own.

1. Choose the missing number in each number pattern.
a) 575; 550; 525; ______; 475
A 425 B 400 C 500 D 450
b) 770; 780; 790; ______; 810
A 600 B 720 C 750 D 800
c) 629; 729; 829; 929; ______
A 1 290 B 1 029 C 1 209 D 1 092
d) 221; 223; 225; 227; ______
A 229 B 231 C 228 D 232
e) 454; 456; 458; ______; 462
A 459 B 500 C 460 D 452
2. Complete each pattern.
a) 9 000; 7 000; 5 000; __________; 1 000
b) 10 000; 8 000; 6 000; __________; 2 000
c) 8 000; 4 000; 2 000; 1 000; __________
3. Fill in <, > or = to make the correct number statement.
a) 2 694 _____ 2 964 b) 5 085 _____ 5 058
Share your solutions with the class.
Record your score out of 10 on your Mental Maths grid.

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Cambridge University Press
978-1-316-61134-0 — Cambridge Mental Maths Grade 4
Zonia Jooste
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TERM 1 • WEEK 1 Mental Maths Workbook • Grade 4

Activity 2 Represent and round off numbers; place value

Content Area: Numbers, operations and relationships
Topic 1.1: Whole numbers

Work with the class.

1. Round off each number at a dot to the nearest 5, 10 and 100.

890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910

Look for the 2. Which number is represented on each abacus?

multiples of 5, a) b) c)
10 and 100 that
are closest to
the number you
must round off.

TH H T U TH H T U TH H T U
We say one ______________ ______________ ______________
abacus, and
many abacuses
or abaci. Work on your own.
1. Write the value of the underlined digit in each number.
a) 6 781 __________ b) 9 503 __________
c) 2 974 __________ d) 8 166 __________
2. The number 7 628 rounded off to the nearest:
a) 10 is → A 7 620 B 7 720 C 7 630 D 7 640
b) 100 is → A 7 700 B 7 600 C 8 600 D 7 500
c) 1 000 is → A 7 000 B 8 000 C 6 000 D 7 000
3. Choose the correct term to describe the numbers in each sequence.
Even numbers Multiples of 5 Odd numbers
a) 21; 23; 25; 27; 29 _________________________________________
b) 60; 58; 56; 54; 52 _________________________________________
c) 0; 5; 10; 15; 20 _________________________________________
Share your solutions with the class.
Record your score out of 10 on your Mental Maths grid.

Activity 3 Commutative property; properties of zero; patterns in

calculations with multiples of 10, 100 and 1 000
Content Area 2: Patterns, functions and algebra
Topic 2.3: Number sentences
Number
sentence: Work on your own.
4 + 3 = 7. 1. Fill in the missing number to make each statement true.
Open number
a) 14 × 4 = 4 × ______ b) 16 + 7 = ______ + 16
sentence:
4+ n = 7. c) 4 × 5 = ______ × 4

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978-1-316-61134-0 — Cambridge Mental Maths Grade 4
Zonia Jooste
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Mental Maths Workbook • Grade 4 TERM 1 • WEEK 1

2. Complete the number sentences.

a) 20 – 6 = ________ 200 – 6 = ________ 2 000 – 6 = ________
b) 40 – 5 = ________ 400 – 5 = ________ 4 000 – 5 = ________
c) 3 × 3 = ________ 30 × 3 = ________ 300 × 3 = ________
A number
sentence is d) 8 ÷ 4 = ________ 80 ÷ 4 = ________ 800 ÷ 4 = ________
also called an e) 7 + 9 = ________ 70 + 90 = ________ 700 + 900 = ________
equation.
3. Complete each equation.
a) 31 – 31 = _____ b) 78 – 78 = _____
c) 123 – 123 = _____ d) 10 – 2 + 2 = _____
e) 20 – 5 + 5 = _____ f) 30 – 6 + 6 = _____
4. Write whether each statement is true or false.
a) 6 + 7 = 7 + 6 _________ b) 14 – 4 = 4 – 14 __________
c) 6 ÷ 3 = 3 ÷ 6 _________
5. Fill in the missing symbol to make each statement true.
♦
a) If n + = ▲, then ▲ + = _________ ♦
♦ ♦
b) If n × n = , then ÷ n = _________
c) If ▲ – ★ = n, then n + ★ = _________
Share your solutions with the class.
Divide your score by 3. Then record your score out of 10 on your Mental Maths grid.

Activity 4 Write and solve number sentences and operations in

brackets
Content Area 2: Patterns, functions and algebra
Topic 2.3: Number sentences

Work with the class.

1. Calculate the total number of cubes and cylinders in each diagram.
Write number sentences on the board to show your thinking.
a) b)

________________________ __________________________
2. Write a number sentence for each word sentence.
a) Eight divided by four is equal to ten divided by five.
________________________________________________________
b) Double twelve is equal to three times eight.
________________________________________________________

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978-1-316-61134-0 — Cambridge Mental Maths Grade 4
Zonia Jooste
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TERM 1 • WEEK 1 Mental Maths Workbook • Grade 4

First solve
Work on your own.
operations
in brackets, 1. Complete each number sentence.
then multiply a) 18 = 6 × ______ b) 0 × (15 – 8) + 4 = ______
or divide,
then add or c) ______ = 30 ÷ 5 d) 7 + (12 – 9) × 0 = ______
subtract from 2. Write a number sentence for each word sentence.
left to right.
a) Half of twenty is equal to fifty divided by five.
________________________________________________________
b) Four multiplied by four is equal to half of thirty-two.
________________________________________________________
c) Double fifteen is equal to fifty minus twenty.
________________________________________________________
3. Fill in the missing number in each equation.
a) (3 × 7) + 4 + (5 × 0) = _______
b) 12 + 34 = 10 + 2 + _______ + 4
c) 29 + 16 = 29 + 1 + _______
Share your solutions with the class.
Record your score out of 10 on your Mental Maths grid.

Activity 5 Solve number sentences by inspection, substitution and

inverse operations
Content Area 2: Patterns, functions and algebra
Topic 2.3: Number sentences

Work with the class.

1. Discuss the learners’ number puzzles and the methods used.

I think of a number. Zinzi

I think of a number. I multiply
I add 5 and divide by 3. it by 4 and subtract 6. My
My answer is 7. What answer is 22. What number
number am I thinking of? am I thinking of?
Ali

Multiply for division ■+5÷3=7 ■ × 4 – 6 = 22

Add for subtraction
and subtract 7×3–5=■ 22 + 6 ÷ 4 = ■ and divide for
for addition. 21 – 5 = ■ 28 ÷ 4 = ■ multiplication.
21 – 1 – 4 = ■
7=■
20 – 4 = 16
Substitute the 7 × 4 – 6 = 22 Substitute the
number to check. 16 + 5 ÷ 3 = 7 number to check.
Zinzi thinks of 16. Ali thinks of 7.

× and ÷ are
inverse 2. Use inverse operations to solve each equation.
operations.
a) _____ – 8 × 4 = 28
+ and – are
also inverse b) _____ ÷ 6 + 7 = 13
operations.

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978-1-316-61134-0 — Cambridge Mental Maths Grade 4
Zonia Jooste
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Mental Maths Workbook • Grade 4 TERM 1 • WEEK 2

Work on your own.

1. Complete each equation.
a) _____ + 9 ÷ 5 = 6 b) _____ × 3 – 6 = 18
2. Fill in the missing number to solve each equation.
a) 10 × _____ = 8 × 5 b) 5 × _____ = 20 + 5
c) 6 × 6 = 18 × _____
Share your solutions with the class.
Multiply your score by 2. Then record your score out of 10 on your Mental Maths grid.

Activity 6 Basic addition and subtraction facts

Content Area 1: Numbers, operations and relationships
Topic 1.1: Addition and subtraction

Work on your own.

1. Fill in the missing number to make each statement true.
a) 100 – 60 = ______ b) 40 + _____ = 100
c) 200 – 10 = ______ d) 70 + _____ = 300
2. Complete each number sentence. Look for patterns.
a) 7 + 2 = _______ b) 13 – 9 = ________
70 + 20 = ________ 130 – 90 = ________
700 + 200 = ________ 1 300 – 900 = ________
3. Complete these basic addition and subtraction facts.
9+7= 16 – 7 = 18 + 5 = 17 – 9 = 28 + 5 =
19 + 7 = 26 – 7 = 28 + 5 = 37 – 9 = 68 + 5 =

Share your solutions with the class.

Divide your score by 2. Then record your score out of 10 on your Mental Maths grid.

Activity 7 Inverse operations and the associative property

Content Area 1: Numbers, operations and relationships
Topic 1.1: Addition and subtraction

Work on your own.

1. Use inverse operations to complete each number sentence.
a) 10 + ______ = 90 b) 100 + ______ = 900
c) ______ + 20 = 100 d) ______ + 30 = 90
e) ______ – 80 = 80 f) ______ – 70 = 70
2. Fill in the missing number to make each statement true.
a) (6 + 8) + 12 = 6 + (12 + _____ )
b) (16 – 9) – 7 = 16 – ( ____ – 7)
c) 23 + (9 + 7) = (23 + ____ ) + 9
d) 45 – (8 – 5) = (45 – ____ ) – 8
Share your solutions with the class.
Record your score out of 10 on your Mental Maths grid.

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978-1-316-61134-0 — Cambridge Mental Maths Grade 4
Zonia Jooste
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TERM 1 • WEEK 2 Mental Maths Workbook • Grade 4

Activity 8 Build up and break down to add, subtract and

compare numbers
Content Area 1: Numbers, operations and relationships
Topic 1.1: Addition and subtraction

Work with the class.

1. Explore the strategies used to add and subtract using multiples
of 100 and 1 000.

Which number is Which number is

6 more than 196? 8 less than 1 002?
196 + 4 + 2 = 200 + 2 1 002 – 2 – 6 = 1 000 – 6
= 202 = 994

2. Use the methods above to solve these problems.

a) Which number is 9 more than 297? ____________
b) Which number is 7 more than 995? ____________

Work on your own.

Use the methods above to solve these problems.

Try to do the
1. Which number is:
calculations in a) 8 more than 96 __________
your head. b) 7 more than 238 __________
c) 9 more than 1 094 __________
d) 6 more than 898 __________
e) 5 more than 2 999? __________
2. Which number is:
a) 7 less than 104 __________ b) 9 less than 506 __________
c) 8 less than 802 __________ d) 6 less than 254 __________
e) 4 less than 3 002? __________
Share your solutions with the class.
Record your score out of 10 on your Mental Maths grid.

Activity 9 Add and subtract using properties of numbers

Content Area 1: Numbers, operations and relationships
Topic 1.1: Addition and subtraction

Work with the class.

♦ that makes each statement true.
1. Find the number to replace
a) 18 + 12 = + 18 ♦ ♦ = __________
♦
b) 24 + 9 + 6 = 24 + + 9 ♦ = __________
c) 1 879 + 8 = 8 + ♦ ♦ = __________
6

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978-1-316-61134-0 — Cambridge Mental Maths Grade 4
Zonia Jooste
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Mental Maths Workbook • Grade 4 TERM 1 • WEEK 2

d) 45 + 7 + 5 = 45 + 5 + ♦ ♦
= __________
♦
e) 27 + 32 = + 7 + 30 + ♦ ♦
= __________
f) 64 – 8 – 4 = 64 – – 8 ♦ ♦
= __________
2. Solve the equations in question 1.
a) __________ b) __________ c) __________
d) __________ e) __________ f) __________
You swap, group
and regroup 3. Discuss how you found the number in each statement in class.
numbers to add
and subtract. Work on your own.
Find the missing number to make each statement true. Then solve each
equation.
1. 27 + 13 = 13 + _______ = ___________________________
2. 46 – 9 – 6 = 49 – ______ – 9 = ___________________________
3. 38 + 31 = 30 + 8 + ______ + 1 = ___________________________
4. 44 – 13 = 44 – 10 + 4 – ______ = ___________________________
5. (57 + 9) + 3 = 57 + ______ + 9 = ___________________________
Share your solutions with the class.
Record your score out of 10 on your Mental Maths grid.

Activity 10 Break up numbers to add and subtract

Content Area 1: Numbers, operations and relationships
Topic 1.1: Addition and subtraction

Work with the class.

1. Explore and discuss the strategies that show how to add and subtract
→ shows a
calculation still by breaking up numbers into place value parts.
in progress.
= indicates the
43 + 68 =
last step.
40 + 60 + 3 + 8 → 100 + 11 = 111

67 – 49 =
(50 – 40) + (17 – 9) → 10 + 8 = 18

2. Use the strategies to solve these problems.

a) 74 + 49 = _______
b) 83 – 37 = _______
3. Without calculating, choose the expression that does not have the same
value as 146 + 72.
A 140 + 70 + 8
B 140 + 60 + 10 + 8
C 140 + 60 + 8

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978-1-316-61134-0 — Cambridge Mental Maths Grade 4
Zonia Jooste
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TERM 1 • WEEK 2 Mental Maths Workbook • Grade 4

Work on your own.

1. Show how to break up numbers to add and subtract.
a) 65 + 57 = _______________________________________________
b) 78 + 49 = _______________________________________________
c) 54 – 28 = ________________________________________________
2. Solve these problems.
a) Alex had 81 marbles. He lost 56 marbles. How many marbles does
he have left? ____________
b) Mary saved R73. Her father gives her R69 more. How much money
does Mary have now? _____________
Share your solutions with the class.
Multiply your score by 2. Then record your score out of 10 on your Mental Maths grid.

Activity 11 Use near doubles to add

Content Area 1: Numbers, operations and relationships
Topic 1.1: Addition and subtraction

Work with the class.

1. About how much is:
a) double 128 b) double 296?
________________________ __________________________
2. Zoe uses near doubles to add. Explore and explain her methods.

128 + 125 = 244 + 247 =

130 + 130 = 260 240 + 240 = 480
260 – 2 – 5 = 260 – 5 – 2 480 + 4 + 7 = 480 + 7 + 4
= 255 – 2 = 487 + 3 + 1
= 253 = 491

3. Aviwe achieved 99 marks in each of the two tests he wrote. How many
marks did he score in the two tests altogether? ______________

Work on your own.

1. Use near doubles to add the numbers.
a) 56 + 58 = _____________________________________________
b) 113 + 119 = _____________________________________________
c) 88 + 87 = _____________________________________________
2. Solve the word problems using near doubles.
a) A goat weighs 39 kg. A sheep weighs twice as much. What is the
mass of the sheep? ______________
b) What is double the sum of 47 + 45? ______________
Share your solutions with the class.
Multiply your score by 2. Then record your score out of 10 on your Mental Maths grid.

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978-1-316-61134-0 — Cambridge Mental Maths Grade 4
Zonia Jooste
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Mental Maths Workbook • Grade 4 TERM 1 • WEEK 3

Activity 12 Do addition to subtract

Content Area 1: Numbers, operations and relationships
Topic 1.1: Addition and subtraction

Work with the class. R100 – R37 = n

1. Aziza bought a pen for R37. 37 + 3 = 40
How much change did she get 40 + 60 = 100
if she paid with a R100 note? 60 + 3 = 63
Count on or add Explore and discuss Aziza’s Aziza got R63 change.
to subtract R37 strategy to calculate the change.
from R100. 2. Show how to subtract 278 from 1 000 using addition.
___________________________________________________________

Work on your own.

1. Add or count on to calculate.
a) R100 – R44 = _______________
b) 1 000 – 766 = _______________
c) 2 000 – 250 = _______________
d) 1 195 + _______________ = 2 000
e) 3 300 + _______________ = 4 000
2. a) Kay buys a toy for R68,60. Circle the coins and notes she uses to
pay for the toy.
R10,00 R50,00 R20,00 R5,00 R2,00

R1,00 50c 20c 10c

b) How much change will Kay get if she pays with R100? __________
Share your solutions with the class.
Question 2.a) is 4 marks. Record your score out of 10 on your Mental Maths grid.

Activity 13 Solve problems

Content Area 1: Numbers, operations and relationships
Topic 1.1: Addition and subtraction

Work on your own.

Solve these word problems.
1. A hawker has 165 apples. He sold some apples and has 96 apples left.
a) Which calculation tells you how many apples the hawker has left?
A 165 + 96 B 165 × 96
C 165 – 96 D 165 ÷ 95
b) Now solve the problem.
________________________________________________________
2. Zukiswa has 84 beads. She uses 58 beads to make a bracelet.
How many beads does she have left?
_________ beads

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978-1-316-61134-0 — Cambridge Mental Maths Grade 4
Zonia Jooste
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TERM 1 • WEEK 3 Mental Maths Workbook • Grade 4

3. A farmer’s chickens laid 68 eggs on Monday and 66 eggs on Tuesday.

How many eggs did the chickens lay in two days?
_________ eggs
4. Crispin buys a chocolate for R7,25. How much change does he get
from R10,00?
R_________
5. Kim has R157. Her sister has R139. How much money do they have
altogether?
R_________
Share your solutions with the class.
Multiply your score by 2. Then record your score out of 10 on your Mental Maths grid.

Activity 14 Complete and describe numeric patterns

Content Area 2: Patterns, functions and algebra
Topic 2.1: Numeric patterns

Work with the class.

1. Find the missing number in each number pattern.
a) 700; 675; 650; 625; 600; _______
b) 800; 400; 200; _______; 50
c) 40; 32; 24; _______; 8; 0
d) 250; 260; 270; 280; 290; _______
e) 500; 1 000; 2 000; 4 000; _______
2. Describe each number pattern above.

Work on your own.

1. Write the next number in each pattern.
a) 90; 92; 94; 96; 98; _______
b) 75; 73; 71; _______
c) 100; 125; 150; 175; _______
d) 80; 40; 20; 10; _______
2. Fill the missing numbers in each pattern.
a) 746; 846; 946; _______
b) 16; 20; 24; _______; 32
c) 1 055; 2 055; 3 055; _______; 5 055
3. Fill in the missing numbers in the last diagram.
2 6 10

14 21 28

4 8 12

Share your solutions with the class.

Record your score out of 10 on your Mental Maths grid.

10

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