Adding and subtracting

Adding puts amounts together; subtracting takes an amount away or finds the difference. There are lots of ways to do it in your head: counting on, using number bonds, and jumping along a number line.

Key facts

  • You can add in any order: 3 + 8 = 8 + 3.
  • Subtraction is the opposite (inverse) of addition: if 8 + 5 = 13, then 13 − 5 = 8.
  • Finding the difference: count up from the smaller number.
  • Bridge through 10: 8 + 5 = 8 + 2 + 3 = 13.

Worked examples

Example 1

Work out 8 + 5.

  1. 8 needs 2 to make 10. 8 + 2 = 10
  2. 5 is 2 + 3, so add the other 3. 10 + 3 = 13

Answer: 13

Example 2

Find the difference between 34 and 52.

  1. From 34 to 40 is 6.
  2. From 40 to 52 is 12.
  3. 6 + 12 = 18 52 − 34 = 18

Answer: 18