2nd grade · Math · Unit 2 of 16
Facts to 20
Add and take away
What your child practices
Fluent facts to 20 using strategies like making ten and thinking addition to subtract.
Maine Learning Results learning standard: 2.OA.B.2 · fluently adding and subtracting within 20
How we explain it
Children can open this short lesson before they practice.
- Use 10 as a stepping stone.
- Break one number to make a 10 with the other.
- Then add what is left over.
Example: 8 + 5 = ? 8 needs 2 more to make 10. Take 2 from 5. That leaves 3. 10 + 3 = 13. Answer: 13
Facts to 20 in Maine
In the Maine Learning Results, this is unit 2 of 16 in 2nd grade Math, after Bigger or Smaller and before Adding to 100.
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 10 − 8?
10 − 8 = ?
- 7
- 6
- 2
2
Hint: Think addition: 8 + ? = 10. Or start at 10 and count back 8.
Question 2
What number is missing?
4 + = 11
- 7
- 5
- 8
7
Hint: Count up from 4 to 11. How many jumps did you make?
Question 3
What is 19 − 3?
19 − 3 = ?
- 16
- 15
- 14
16
Hint: Think addition: 3 + ? = 19. Or start at 19 and count back 3.
Question 4
What is 16 − 3?
16 − 3 = ?
- 3
- 13
- 18
13
Hint: Think addition: 3 + ? = 16. Or start at 16 and count back 3.
Question 5
What is 7 + 6?
7 + 6 = ?
- 11
- 16
- 13
13
Hint: Make a ten! 7 + 3 = 10, then add 3 more to get 13.
Question 6
What is 9 + 7?
9 + 7 = ?
- 16
- 14
- 15
16
Hint: Make a ten! 9 + 1 = 10, then add 6 more to get 16.