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.
Maine Learning Results learning standard: 1.NBT.C.4; 1.NBT.C.5; 1.NBT.C.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
Jump by Tens in Maine
In the Maine Learning Results, this is unit 13 of 14 in 1st grade Math, after Hour & Half Hour and before Picture Graphs.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Source: Maine Department of Education
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 32 + 40?
32 + 40 = ?
- 72
- 62
- 73
- 36
72
Hint: Add the tens: 30 + 40. Keep the 2 ones.
Question 2
What is 82 + 8?
82 + 8 = ?
- 80
- 100
- 89
- 90
90
Hint: Add the ones first: 2 + 8 = 10.
Question 3
What is 10 less than 36?
- 25
- 35
- 26
- 27
26
Hint: Take away one ten. The ones digit stays the same.
Question 4
What is 10 more than 85?
- 185
- 86
- 96
- 95
95
Hint: Add one ten. The ones digit stays the same.
Question 5
What is 50 − 20?
50 − 20 = ?
- 0
- 3
- 30
- 60
30
Hint: 5 tens take away 2 tens is 3 tens.
Question 6
What is 50 − 30?
50 − 30 = ?
- 30
- 20
- 2
- 10
20
Hint: 5 tens take away 3 tens is 2 tens.