NumberKS3 / GCSE

Adding and subtracting negative numbers

Add signed numbers and subtract negatives using opposites.

  • Adding a positive moves right on a number line. Adding a negative moves left.
  • Subtracting a number means adding its opposite: .
  • After changing a subtraction to addition, compare the sizes and signs.

Example 1

Adding a negative

Evaluate the expression.

Example 2

Subtracting a negative

Calculate the value of the expression.

Remember
“Two negatives make a positive” is a multiplication rule. For adding or subtracting, follow the operations.

Your turn

Question 1

Calculate.

Check answer
Question 2

Calculate.

Check answer
Question 3

Calculate.

Check answer
Question 4

Calculate.

Check answer
Question 5

Calculate.

Check answer