1st grade · Math · Unit 13 of 14
Jump by Tens
10 more, 10 less
What your child practices
Finding 10 more and 10 less than a number in their head, subtracting tens, and adding ones or tens to a two-digit number.
Washington State Learning Standards learning standard: M.1.R.NBT.4; M.1.R.NBT.5; M.1.R.NBT.6 · finding 10 more and 10 less, subtracting multiples of 10, and adding within 100
How we explain it
Children can open this short lesson before they practice.
- 10 more: the tens digit goes up 1.
- 10 less: the tens digit goes down 1.
- The ones digit stays the same.
Example: What is 10 more than 47? 4 tens become 5 tens. The 7 ones stay. Answer: 57
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
What is 80 − 20?
80 − 20 = ?
- 50
- 60
- 70
- 6
60
Hint: 8 tens take away 2 tens is 6 tens.
Question 2
What is 10 less than 41?
- 31
- 30
- 51
- 40
31
Hint: Take away one ten. The ones digit stays the same.
Question 3
What is 23 + 10?
23 + 10 = ?
- 34
- 33
- 24
- 23
33
Hint: Add the tens: 20 + 10. Keep the 3 ones.
Question 4
What is 10 more than 58?
- 158
- 69
- 68
- 48
68
Hint: Add one ten. The ones digit stays the same.
Question 5
What is 29 + 8?
29 + 8 = ?
- 37
- 36
- 27
- 47
37
Hint: Add the ones first: 9 + 8 = 17.
Question 6
What is 10 less than 86?
- 77
- 96
- 75
- 76
76
Hint: Take away one ten. The ones digit stays the same.