1st Grade Number Hunt: Sums to 20 Worksheets
Fresh practice, ready to print. Answer key included.
Number puzzles with numbers up to 20. In each group, one number is the sum of two others: children test pairs in their head until they find it, then write the addition sentence.
Make it yours
Or start with a ready-made version.
What's on the worksheet
- Find the sum
Five numbers up to 20, such as 4, 9, 13, 16 and 19.
- Challenge: six numbers
Six numbers in each group, so there are more pairs to try.
How it works: a quick refresher
The rules this worksheet practices, then one problem worked from start to finish.
| Strategy | How it works |
|---|---|
| Pick a number, then look for its pair | For 13, ask: what goes with 4 to make 13? 9. Is 9 here? |
| Make ten to add | 8 + 5: 8 and 2 make 10, and 3 more is 13. |
| The answer is never the biggest | Every group has a number bigger than the answer, so test each one. |
| Cross off as you go | A number that can't be made from two others gets a small line through it. |
Worked example
Find the number made from two others: 4, 9, 13, 16 and 19.
- 1Try 4 + 9 = 13. 13 is in the group.
- 2Check the bigger ones: 16 − 4 = 12, 16 − 9 = 7 and 16 − 13 = 3 are not here, and neither are 15, 10, 6 or 3 for 19.
- 3Circle 13 and write 4 + 9 = 13.
Ready-made versions
Three fixed versions you can link to or share. Each is a PDF with its own answer key.
- 1st Grade Number Hunt: Sums to 20 Worksheets, version 1Worksheet PDFAnswer key PDF
- 1st Grade Number Hunt: Sums to 20 Worksheets, version 2Worksheet PDFAnswer key PDF
- 1st Grade Number Hunt: Sums to 20 Worksheets, version 3Worksheet PDFAnswer key PDF
Grade level and standard
Written for 1st grade math (puzzles) and aligned to CCSS 1.OA.C.6. It also works as review in later grades.
Common questions
- Is there an answer key?
- Yes. Every worksheet has a matching answer key with each answer worked on the same grid or layout as the question. The worksheet code printed at the bottom of each page pairs a sheet with its key.
- Why puzzles instead of a page of facts?
- To find the answer, children add many pairs and compare the totals, so they practice far more facts than the page shows, and they choose which ones.
- Is there a version to play on screen?
- Yes. Flip's Number Hunt has the same puzzles as a free game: endlessworksheets.com/games/number-hunt/sums-to-20.
- How many different versions are there?
- About a million per skill. Each time you press the button the problems are generated fresh, so you can print a different version for every student, a retake, or another night of practice.
- Are the worksheets free?
- Yes. They are free to print and copy for your home or classroom, with no sign-up.
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