

How to use this book
Each Year 7 topic is presented on a two-page spread
Organise your knowledge with concise explanations and examples
Key points highlight fundamental ideas
Notes help to explain the mathematical steps
Mixed questions further test retrieval skills after all topics have been covered
Key facts and vocabulary section helps to consolidate knowledge of mathematical terms and concepts
Test your retrieval skills by trying the accompanying questions for the topic
Answers are provided to all questions at the back of the book
ACKNOWLEDGEMENTS
The authors and publisher are grateful to the copyright holders for permission to use quoted materials and images. Every effort has been made to trace copyright holders and obtain their permission for the use of copyright material. The authors and publisher will gladly receive information enabling them to rectify any error or omission in subsequent editions. All facts are correct at time of going to press.
All images ©Shutterstock and HarperCollinsPublishers
Published by Collins
An imprint of HarperCollinsPublishers Limited

1 London Bridge Street
London SE1 9GF
HarperCollinsPublishers
Macken House
39/40 Mayor Street Upper Dublin 1
D01 C9W8
Ireland
© HarperCollinsPublishers Limited 2023
ISBN 9780008598648
First published 2023
10 9 8 7 6 5 4 3 2 1
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted,
in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of Collins.
British Library Cataloguing in Publication Data.
A CIP record of this book is available from the British Library.
Authors: Leisa Bovey, Ama Dickson and Katherine Pate
Publisher: Clare Souza
Commissioning and Project Management: Richard Toms
Inside Concept Design and Layout: Ian Wrigley and Nicola Lancashire
Cover Design: Sarah Duxbury
Production: Emma Wood
Printed in India
Negative numbers
Positive and negative temperatures and numbers
Temperatures below freezing (0°C) are negative.
The temperature is –3°C. It rises by 5°. What is the new temperature?


Write these temperatures in order, from coldest to hottest:
7°C –9°C 0°C 3°C
Find the numbers on a number line.
Start at –3°C and count up 5° Write the correct sign (< or >) between each pair of numbers:
Find
The new temperature is 2°C.
Adding and subtracting negative numbers
Adding a negative number is the same as subtracting, e.g. 3 + -2 = 3 - 2 = 1
Subtracting a negative number is the same as adding, e.g. 3 - -2 = 3 + 2 = 5
Multiplying and dividing negative numbers
positive × or ÷ negative = negative
e.g. 6 × -3 = -18 6 ÷ -3 = -2
negative × or ÷ positive = negative
e.g. -10 × 2 = -20 -10 ÷ 2 = -5
Each counter represents –1. Write two multiplication facts and two division facts for this array.
negative × or ÷ negative = positive
e.g. -10 × -5 = 50 -10 ÷ -5 = 2
Work out:
a) 3 × –5 3 × –5 = –15
b) –3 × 5 –3 × 5 = –15
c) –3 × –5 –3 × –5 = +15
d) 12 ÷ –3 12 ÷ –3 = –4
4 × –2 = –8 –8 ÷ 4 = –2
2 × –4 = –8 –8 ÷ 2 = –4
e) –12 ÷ 3 –12 ÷ 3 = –4
f) –12 ÷ –3 –12 ÷ –3 = +4
You don’t need to write the + sign in your answer.
Negative numbers



Positive and negative temperatures and numbers
1 Use the thermometer to help answer these questions.
a) The temperature is –2°C. It rises by 4°.
What is the new temperature?
b) The temperature is 3°C. It falls by 7°.
What is the new temperature?
c) What is the difference in temperature between these two cities?
London: 10°C Oslo: –5°C
d) Write these temperatures in order, from hottest to coldest: –4°C 8°C –7°C 1°C –9°C
2 Write the correct sign (< or >) between each pair of numbers.
Adding and subtracting negative numbers
3 Work out:
5 + –5
7 – –4 c) 250 + –100
e) –13 – –3
Multiplying and dividing negative numbers
4 Work out:
a) –30 ÷ 10
c) –100 ÷ –20
e) –5 × –7
5 Work out:
a) –4 + 10 ÷ 5
b) –5 × (3 – 7)
c) 3 × –6 – 24 ÷ –8
d) 15 ÷ –5 + 4 × –3
6 Fill in the missing numbers in these calculations.
a) 8 + 2 – 2 – = 0
c) 12 + 5 – 12 – = 0
–9 × 2
–6 × 5
28 ÷ –4
–5 + 5 – 2 + = 0
–270 + 70 + = 0
Multiplication and division
Multiplying and dividing with positive and negative integers
When multiplying or dividing a positive number by a negative number, the result is negative When multiplying or dividing a negative number by a negative number, the result is positive
5 × 1 = 5 –2 × 1 = –2
5 × 0 = 0 –2 × 0 = 0
5 × –1 = –5 –2 × –1 = 2
a) Calculate 6 × 3 + + = 6 × 3 = 18
When multiplying a positive number by a positive number, the result is positive (+ × + = +). 6 × 3 is the same as adding 3 lots of 6.
b) Calculate –8 × 3
–8 × 3 = –24 – × + = –
c) Calculate 8 × –3
8 × –3 = –24 + × – = –
d) Calculate –7 × –4
–7 × –4 = 28 – × – = +
Multiplication is commutative, so a × b = b × a . For example, 4 × 3 = 12 and 3 × 4 = 12
e) Calculate 15 ÷ 5
There are 15 dots with 5 dots in each group. There are 3 groups of dots.
15 ÷ 5 = 3
f) Calculate –20 ÷ 4
–20 ÷ 4 = –5 – ÷ + = –
g) Calculate 20 ÷ –4
20 ÷ –4 = –5 + ÷ – = –
h) Calculate –28 ÷ –7
–28 ÷ −7 = 4 – ÷ – = +
Multiplying and dividing with decimals
When multiplying a number by another number that is less than 1, the value decreases.
Work out 0.09 × 0.7 0.09 × 0.7 × 10 × 100 9 × 7 = 63 ÷ 1000 = 0.063
A dividend is the number that is being divided.
Multiply both numbers so they are whole numbers.
100 × 10 = 1000, so divide 63 by 1000 to get 0.063
A divisor is a number that divides another number and may leave a remainder.
divisor quotient dividend
20 ÷ 4 = 5
A quotient is the result of dividing one number by another.
When dividing with decimals, multiply each number by 10 until the divisor is a whole number.
2 goes into 18 nine times.
also goes into 1.8 nine times.
The calculations are equivalent.
b)
4 1 13 16 Ensure that the decimal points are lined up.
So, 1.36 ÷ 0.4 = 3.4
Multiplying and dividing with positive and negative integers
1 Work out:
7 × 8
9 × 6 c) –6 × 2
–5 × 10
2 Work out:
7 × –2
4 × –8 c) –2 × –3
–12 × –8
3 Work out:
4 Work out:
Multiplying and dividing with decimals
3 The distributive law
Using the distributive law
When multiplying a term by a group of terms added together, the result is the same as when multiplying each number separately and then adding them.
Using the distributive law, 4 × 8 can be written as:
4 × (2 + 6) = 4 × 2 + 4 × 6
a (b + c) = a b + a c
a (b – c) = a b – a c
Complete the calculation by finding the missing number.
24 × 36 = 24 × 9 ×
To find the missing number, think about the factors of 36.
9 is a factor of 36 and is multiplied by 4 to make 36. Therefore, 9 and 4 are factor pairs
The missing number is 4.
A factor is a number that divides into another number without leaving a remainder.
3 × 48 can be written as 3 × (40 + 8)
Algebraically, this is written as 3(40 + 8)
This can be solved by multiplying the term outside the brackets with each term inside the brackets.
(3 × 40) + (3 × 8)
= 120 + 24 = 144
Using the distributive law, 3 × 48 can be written as 3 × (50 – 2)
Algebraically, this is written as 3(50 – 2)
Solving:
(3 × 50) + (3 × –2)
= 150 – 6 = 144
The calculation 4 × 12 can be solved in this way using the distributive law:
4(7 + 2 + 3) = (4 × 7) + (4 × 2) + (4 × 3)
= 28 + 8 + 12 = 48
3 The distributive law
Using the distributive law
1 Complete each calculation by finding the missing number.
a) 63 × 14 = 63 × 2 ×
b) 54 × 27 = × 2 × 27
2 Using the distributive law, write the calculation that is represented by this area model: 6
4 5
3 Complete the calculation by finding the missing numbers.
5 × 15 = 5(4 + ) = (5 × ) + (5 × )
4 Solve the following by using the distributive law.
a) 5(6 + 2)
b) 8(3 + 4)
c) 6(5 – 2)
5 Solve the following by using the distributive law.
a) 9(5 + 7 + 1)
b) 7(8 + 3 + 2)
Mixed questions
1 Reflect the shape in the dashed mirror line.
2 What does the digit 3 represent in each of these numbers?
a) 131 279
b) 0.101 348
3 a) Convert 4 3 8 to an improper fraction.
b) Convert 25 7 to a mixed number.
4 Write down the ratio of blue counters to red counters to yellow counters. Give your answer in its simplest form.
5 Calculate:
−17 + −9
12 − −18
0.8 × 0.4
6 Write each fraction in its simplest form.
9 36
Mixed questions
7 The temperature fell to −7 °C one winter’s night. By 9 am, the temperature was 4 °C.
By how much had the temperature risen?
8 Enlarge this shape by scale factor 3 about centre C.
9 a) Find the highest common factor of 24 and 42.
b) Find the lowest common multiple of 6 and 10.
10 Find the perimeter and the area of this trapezium.
Perimeter =
Area =
11
Calculate:
a) 5 × (8 – 3) + 10 × 3 – 1
b) 5 × 8 – (3 + 10) × 3 – 1
12 Amy and her friends share a birthday cake. Amy eats 1 6 of the cake and her friends eat 2 3 of the remainder.
What fraction of the cake is left?
Key facts and vocabulary
Adding and subtracting Line up the digits by place value
Convert fractions to equivalent fractions with the same denominator
–3 12 = 15 24 –6 24 = 9 24 = 3 8
Dividing Use place value to divide by 10, 100, 1000
In fractions, keep the first fraction the same, flip the second fraction, change ÷ to ×
Equivalent Represent the same amount or proportion
Factor A number that divides exactly into another number Fraction 3 4 Numerator Denominator
Highest common factor (HCF)
The highest factor that two numbers share (have in common)
Improper fraction A fraction with a numerator greater than the denominator 13 4 Integer A whole number
Lowest common multiple (LCM)
The lowest multiple that two numbers share (have in common)
Multiples of 12: 12 24 36 48 60 72
Multiples of 18: 18 36 54 72
Mixed number Has a whole number part and a fraction part
Multiple A number in a times table. Multiples of 4 are 4, 8,
Key facts and vocabulary
Multiplying Use place value to multiply by 10, 100, 1000 4.5 × 10 = 45 4.5 × 100 = 450
× 1000 = 4500 In fractions, multiply the numerators and multiply the denominators 3
× 4 7 = 12 35
Power Repeated multiplication of a number by itself
Prime numbers have exactly two factors: 1 and itself; 1 is not a prime number
Inverse of a power
= 3.2 (to 1 decimal place)
than 5 so round down
= 9, so √9 = 3 Square root of 9 is 3.
(to 2 decimal places)