Inverse operations with tens
Inverse operations with tens helps children practise writing the inverse subtraction for a tens addition and vice versa, then using it to check. Read the short guide and look through the examples before choosing online practice or a printable worksheet.
How to solve this
- An inverse task with tens uses the opposite operation: if 40 + 30 = 70, then 70 − 30 = 40 and 70 − 40 = 30.
- Write the related fact family: one addition and two subtractions all use the same three numbers.
- Check that all three equations in the family give the correct result before moving on.
Examples
30 + 40 = 70
70 - 40 = 30
28 + 9 = 37
37 - 9 = 28