Look at the whole equation
The two numbers and the result are already shown. Decide whether joining the numbers or finding their difference makes the equation true.
In 7 ? 4 = 11, the missing sign is plus because the two numbers join to make 11. In 7 ? 4 = 3, the missing sign is minus because taking 4 away from 7 leaves 3. Read the result before deciding; do not choose from the first two numbers alone.
Choose one focused round to practise plus and minus signs within 20. Every equation has one clear answer. The matching printable worksheet gives a child space to record each chosen sign before checking.