Order, add, subtract, multiply and divide negative numbers, including temperature and money contexts. It is a Foundation topic, aimed at grade 1. Free questions with answers are on this page. Worked examples show each line before you try the questions.
Negative numbers live to the left of zero. −5 is smaller than −1 because it is further left, even though 5 is bigger than 1. A number line (or a thermometer) is the safest picture for addition and subtraction: −4+7 means start at −4 and walk 7 to the right, landing on 3. Subtracting a negative is a turn-around: minus a minus becomes plus.
Multiplication and division use a sign rule, not a number line. Two signs the same make a positive; two different signs make a negative. (−6)×(−5)=30 and (−6)×5=−30. Decide the sign first, then work out the size, so the minus does not vanish in the last line.
Temperature questions are differences: from 11∘C to −8∘C you pass through zero, so the drop is 11+8=19 degrees, not 11−8.
Objectives
Place negatives on a number line.
Add and subtract across zero.
Order a set that includes negatives.
Key points
Put positive and negative numbers in order (a number line helps).
Add and subtract with negatives, including 'subtracting a negative'.
Multiply and divide negatives using the sign rules.
Find the difference between two temperatures, one or both negative.
Worked examples
Example 1
The temperature is −4°C and rises by 7 degrees. What is it now?
2 marks
Start at −4.
Move 7 steps right.
−4 + 7 = 3
Answer: 3
Common slips
Slip: Start at 4. A rise from a negative still starts on the negative.
Slip: Move 7 steps left. A rise is a move towards the positives.
Slip: −4 + 7 = −11 Adding a positive does not make the negative “more negative”.
Example 2
A diver stands on a board 2 m above the water. He drops 6 m. Taking the water surface as 0 and down as negative, what is his position?
2 marks
2 − 6
From 2, six steps left.
The position is −4 m.
Answer: -4
Common slips
Slip: 2 + 6 Descending reduces the height.
Slip: Stop at 0. The dive does not stop at the surface.
Slip: The position is 4 m. He has gone past zero, so the position is negative.
Example 3
The overnight temperature is −6°C. It falls by 3 degrees, then rises by 11 degrees. What is the final temperature?
3 marks
−6 − 3 = −9
−9 + 11 = 2
The final temperature is 2°C.
Answer: 2
Common slips
Slip: −6 − 3 = −3 A fall goes further left. −6 then 3 more left is −9.
Slip: −9 + 11 = −20 A rise of 11 from −9 crosses zero.
Slip: The final temperature is −9°C. −9 was only the middle reading.
Questions and answers
GCSE Maths negative numbers questions and answers. Try each one, then open the answer. Easy questions come first.
Question 1 Easy2 marks
What is −1 + 4?
Show answer
Answer: 3
Start at −1 and move 4 right.
−1 + 4 = 3.
M1 — Start at −1 and move 4 right.
A1 — Answer 3
Question 2 Easy2 marks
What is 3 − 8?
Show answer
Answer: -5
From 3, move 8 left.
3 − 8 = −5.
M1 — From 3, move 8 left.
A1 — Answer -5
Question 3 Medium2 marks
What is −7 + 7?
Show answer
Answer: 0
Seven steps right from −7 lands on 0.
−7 + 7 = 0.
M1 — Seven steps right from −7 lands on 0.
A1 — Answer 0
Question 4 Medium2 marks
What is −3 − 4?
Show answer
Answer: -7
Both moves go left.
−3 − 4 = −7.
M1 — Both moves go left.
A1 — Answer -7
Question 5 Hard2 marks
Work out −8 + 3 − 2.
Show answer
Answer: -7
−8 + 3 = −5.
−5 − 2 = −7.
M1 — −8 + 3 = −5.
A1 — Answer -7
Question 6 Hard2 marks
From −12°C the temperature rises by 5 degrees and then by 9 degrees. What is it now?
Show answer
Answer: 2
−12 + 5 = −7.
−7 + 9 = 2.
M1 — −12 + 5 = −7.
A1 — Answer 2
Question 7 Exam-style3 marks
At 6 am the temperature is −4°C. By noon it has risen by 9 degrees, then by 6 pm it has fallen by 3 degrees. What is the 6 pm temperature?
Show answer
Answer: 2
−4 + 9 = 5.
5 − 3 = 2.
M1 — Adds the morning rise
M1 — Subtracts the afternoon fall
A1 — Answer 2
Common mistakes
Most lost marks on this topic are one slip.
Thinking a “bigger” digit with a minus is the greater number. −9 is less than −2.
Further left means smaller. Compare positions, not the faces.
Stopping at zero when a calculation crosses it.
Keep counting in the same direction until the steps run out.
Treating “add a negative” as a move right.
Adding a negative goes left, the same way as subtraction.
Spot the slip
Which is colder, −3°C or 2°C?
−3°C
2°C
They are the same
Show the slip
−3°C On a number line, −3 is left of 2, so it is smaller and colder.
Exam tips
Be ready to do this without a calculator. Paper 1 is the non-calculator paper.
If the question says “show that”, the result is given. The marks are for the steps that reach it.
The method is the same on AQA-style and Edexcel-style papers.
Sketch a quick number line in the margin for any ordering or temperature question; it is fast and reliable.
Write '− − = +' and the sign rules at the top of your working when you start a negatives question.
Printable worksheet
The same questions are in a PDF you can print. Answers start on a later page.