2nd grade · Math · Unit 2 of 14
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.
Minnesota K-12 Academic Standards benchmark: 2.3.5.8 · fluently adding and subtracting within 20 with mental strategies
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 Minnesota
In the Minnesota K-12 Academic Standards, this is unit 2 of 14 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.
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 7 + 4?
7 + 4 = ?
- 11
- 7
- 9
11
Hint: Make a ten! 7 + 3 = 10, then add 1 more to get 11.
Question 2
What is 6 + 7?
- 7
- 13
- 8
13
Hint: Make a ten! 6 + 4 = 10, then add 3 more to get 13.
Question 3
What number is missing?
10 + = 14
- 4
- 8
- 3
4
Hint: Count up from 10 to 14. How many jumps did you make?
Question 4
What is 14 − 7?
14 − 7 = ?
- 7
- 1
- 4
7
Hint: Think addition: 7 + ? = 14. Or start at 14 and count back 7.
Question 5
What is 18 − 7?
18 − 7 = ?
- 11
- 9
- 8
11
Hint: Think addition: 7 + ? = 18. Or start at 18 and count back 7.
Question 6
What is 6 + 4?
6 + 4 = ?
- 10
- 20
- 6
10
Hint: Start at 6 and count up 4 more.