Worked example
27 October 2026
Inverse operations help children solve word problems by working backwards. If your child can spot what is being added or taken away, they can use the opposite operation to find what is missing.
Worked example
A box and 7 apples together weigh 15 kg. The box weighs 3 kg. How much do the apples weigh?
Step 1: Write the calculation. Box + apples = 15 kg.
Step 2: We know the box is 3 kg. So, 3 kg + apples = 15 kg.
Step 3: Use the inverse operation. We do the opposite of adding 3 kg. So, 15 kg - 3 kg = apples.
Step 4: 15 kg - 3 kg = 12 kg.
The apples weigh 12 kg.
| Item | Weight (kg) |
|---|---|
| Box | 3 |
| 7 apples | |
| Box + apples | 15 |
After seeing this example, your child should recognise when to use inverse operations in similar word problems. They can now practise more questions like this to build their confidence.
