Two-digit ± one-digit, with regrouping
When the ones go past 10, split the number so you reach the next ten first: 47 + 6 = 47 + 3 + 3 = 53. Subtraction works the same way in reverse: 53 − 6 = 53 − 3 − 3 = 47.
How to solve this
- When a ones digit goes above 9 or below 0, you must carry into or borrow from the tens.
- For addition: if ones sum to 10 or more, write the ones digit and carry 1 ten to the left. For subtraction: borrow 10 from the tens when ones are not enough.
- Check by using the inverse operation: add and subtract should undo each other.
Examples
46 + 7 = ?
53
82 - 25 = ?
57
34 + 21 = ?
55
Practice problems with answers
Solve these problems on paper or out loud, then check the answer key. The online practice and the printable worksheet give a new set every time.
- 88 − 9 = ___
- 43 − 9 = ___
- 90 − 6 = ___
- 16 + 9 = ___
- 42 + ___ = 51
- 72 + ___ = 80
- ___ − 7 = 75
- 52 − 3 = ___
Show answers
- 79
- 34
- 84
- 25
- 9
- 8
- 82
- 49