Subtract within 20
2 printable PDFs, each with its answer key. These sheets practice subtraction facts within 20, written across, like 15 − 7 = ☐.
Sheet 1
Sheet 2
What's on the sheet
36 problems written across, with a box for each answer, on US Letter paper, with a box for the score. Some from sheet 1:
- 15 − 6 = 9
- 18 − 6 = 12
- 20 − 2 = 18
- 8 − 5 = 3
Helping at home
In 1st grade, children subtract within 20 and become fluent with facts within 10. For the bigger facts they use strategies: counting back, going back to ten (15 − 5 is 10, then 2 more makes 8), and thinking of addition (7 + 8 = 15, so 15 − 7 = 8).
The usual slip is counting back and landing one off. Another is subtracting the digits in the teen number, so 15 − 7 becomes 12 (7 − 5 = 2).
One way to help at home: turn subtraction into a missing number. "7 plus what makes 15?" Children who know their addition facts find this much quicker than counting back. Have your child circle any problem that felt slow; those are the facts to practice tomorrow.
Practice the same skill as a game
In larkit, your child plays this skill on screen, with a second try and a hint when a problem is hard. Free to try, no ads.
Play it freeWant more sheets?
The free sheets above need no email. If you'd like extras, we can send them.
Common Core: 1.OA.C.6