8 - ? = 5
About this exercise
Taking one number away from another.
Example problems
A few of the problems this exercise asks. The printable worksheet holds ten fresh ones.
- 9 − ? = 2
- 3 − ? = 1
- 10 − ? = 7
- 9 − ? = 1
Try it yourself first — open a section below only if you get stuck.
How to solve it
Subtract the ones first, then the tens. If the top digit is too small, exchange one ten from the column to the left.
Worked example
For 70 - 31, the ones need an exchange: 10 - 1 = 9, and 60 - 30 = 30, giving 39.
Common mistake
Subtracting the smaller digit from the larger out of habit. In 70 - 31 the ones column is 0 - 1, which needs an exchange rather than a flip to 1 - 0.