Adding Checks Subtracting
Use adding to check
Clever trick: check a subtraction by adding back! If 8 – 3 = 5, then 5 + 3 should be 8.
8 − 3 = 5
↕ check ↕
5 + 3 = 8 ✓
To check a take away, add the answer back! 8 − 3 = 5, and 5 + 3 = 8, so it is correct. Because adding and subtracting are opposites, one checks the other. Always check your work!