Subtract Within 20 Worksheets for 1st Grade
Subtract two numbers where the larger number can be as high as 20. 15 free printable worksheets, each with an answer key.
Save to PinterestFree Subtract Within 20 Worksheets
Click a worksheet to open the PDF, or grab the matching answer key. Every sheet prints on one page.
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Subtract Within 20: what children learn
This extends single-digit subtraction fluency up to numbers as large as 20 — the same "count back" strategy still works, just with more steps to track.
Subtract Within 20: worked example
15 - 8 = 7
Start at 15 and count back 8: 14, 13, 12, 11, 10, 9, 8, 7. The answer is 7.
Subtract Within 20: a common mistake to watch for
Kids sometimes lose count partway through a longer count-back — using the related addition fact (8 + __ = 15) is often faster and less error-prone at this range.
Subtract Within 20: how to help at home or in class
For a problem like fifteen minus eight, count up from the smaller number rather than back: from eight, how many steps get to fifteen? Practice on a number line drawn with chalk on the driveway, jumping to ten first and then the rest. Talk about why this works and when counting back is easier, such as taking away just one or two. Once your child picks a sensible strategy without prompting, they can work on subtracting tens.
What is on these Subtract Within 20 worksheets
This set has 15 different worksheets for 1st grade, with 23 questions on each and a matching answer key for every sheet. The instruction printed on each worksheet is: “Subtract and write the answer.”
Example questions like the ones on these worksheets, with their answers:
- 6 - 6 =0
- 5 - 4 =1
- 17 - 8 =9
- 18 - 4 =14
- 17 - 13 =4
- 9 - 5 =4
- 15 - 3 =12
- 18 - 12 =6
Every answer on every sheet is checked by a separate program before the worksheet is published. How we check answers