Math worksheet
Addition Within 20 Worksheets
Addition facts with sums up to 20, including the make-a-ten facts like 8 + 5 and 9 + 7.
Free printable PDF
Download this sheet and its answer key as shown, and print it at home or school. No account needed.
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- Grade
- Grade 1
- Ages
- 6–7
- Problems per page
- 20
- Format
- Stacked in columns
- Answer key
- Included
- Paper
- US Letter or A4
About this worksheet
Fluency with addition within 20 is a common first-grade goal. The sheet mixes easy facts with the ones that cross ten, such as 8 + 5 and 9 + 7, which are the facts most children find hardest. A helpful strategy for those is “make a ten”: 8 + 5 is 8 + 2 + 3, which is 10 + 3.
Every sum on the page is 20 or less. If your child is still counting most answers, try a page of addition within 10 first; if most answers come quickly, two-digit addition is next.
- 01
Answer key included
Every sheet ends with a matching answer key page, so checking work takes seconds.
- 02
New problems in one click
Open the sheet in the editor and generate a fresh set with the same settings whenever you need another page.
- 03
Sized for young writers
Large digits with room to write each answer, on US Letter or A4 paper.
Questions
- Which addition facts within 20 are hardest?
- Facts that cross ten, like 7 + 6, 8 + 5, and 9 + 4, usually take longest. Practicing the make-a-ten strategy on these helps more than repetition alone.
- How many problems are on each sheet?
- Twenty problems per page, followed by an answer key page. You can change the number of rows and columns, or add pages, in the editor.
- Are these addition within 20 worksheets free?
- Yes. The sample sheet on this page, with its answer key, is a free PDF in US Letter or A4, no account needed. Generating and previewing new problems is free too; printing and downloading custom sheets come with Pro, which also removes the preview watermark.