How it works
Add tens to tens. Add ones to ones.
If the ones make ten or more, they make a new ten.
Add the new ten to the tens.
Worked examples
Add a ten
- ? = 35 + 10
- The ones stay the same.
- Only the tens change.
- So the answer is 45.
Ones make a new ten
- ? = 39 + 2
- Ones first: add the ones.
- If they make ten or more, move a ten over.
- So the answer is 41.
Add ten to a number
- 17 + 10 = ?
- Look at the tens digit.
- It goes up by one. The ones stay.
- So the answer is 27.
A taste of the worksheet
These are the first problems of set A. The printable sheet has many more, with an answer key.
- 14 + 1 = __
- __ = 94 + 3
- 73 + 3 = __
- 81 + 6 = __
- 92 + 5 = __
Words to know
- tens
- Groups of ten.
- ones
- The single ones left over.
Watch out for
- Add ones to ones and tens to tens.
- Don't forget the new ten when the ones make ten or more.