These 1st grade making 10 worksheets are generated rather than scanned, which means you can print a different sheet every day of the week without paying for a subscription or running out of practice. The version loaded below opens with items in the shape of 9 + □ = 10 and 3 + □ = 10; the key lists 1 and 7 next to their question numbers.
‘New set of problems’ opens the generator in its own tab. There you can change the problem count and turn the answer key on or off. ‘Print or save as PDF’ opens the print dialog — choose Save as PDF in the printer list to keep the file. The sheet fits US Letter and A4, and the answer key prints on its own page.
A missing-number problem such as 9 + □ = 10 asks the child to work backwards, and that is a genuinely different skill from computing forwards. The answer 1 cannot be reached by reading left to right and doing what the sign says.
The sheet mixes the position of the missing value, so the box sometimes sits in the first slot and sometimes in the answer slot. Children who have only met one arrangement usually stall on the other.
The reliable strategy is the inverse operation: to find the box in 7 + □ = 10, undo what is being done. Say that out loud each time until the child says it first.
Missing-number work also exposes memorised facts that are not really known. A child can recite a fact forwards and still be unable to produce 7 when the same fact is presented backwards.
Work of this kind is commonly aligned with the operations and algebraic thinking strand for this grade; schools outside the US meet the same skill at roughly the same age, which is why these 1st grade making 10 worksheets travel well.
| # | Problem | Answer | What to check |
|---|---|---|---|
| 1 | 9 + □ = 10 | 1 | Watch for: freezing when the box is first |
| 2 | 3 + □ = 10 | 7 | Check: guess-and-check without adjusting |
| 3 | 7 + □ = 10 | 3 | Look at: ignoring the box and computing the two visible numbers |
| 4 | 5 + □ = 10 | 5 | Ask about: writing the whole equation as the answer |
| 5 | 1 + □ = 10 | 9 | Watch for: using the same operation instead of the inverse |
| 6 | 8 + □ = 10 | 2 | Check: treating the equals sign as 'the answer comes next' |
Work 5 + □ = 10 out loud as a demonstration. It gives 5. Children who hear 5 + □ = 10 reasoned through once at the start of a session make noticeably fewer errors in the ten minutes that follow.
Here is one worked through. 3 + □ = 10 gives 7. If your child arrives somewhere other than 7 on 3 + □ = 10, look at the working rather than the answer: nearly every wrong result comes from a skipped step, not an unknown fact.
The answer key is generated with the worksheet, not written by hand, so it always matches the sheet in front of you — 9 + □ = 10 is listed as 1, 3 + □ = 10 as 7, and so on down the page.
Answers appear next to their question numbers, so a wrong item like 3 + □ = 10 can be found in the key in a second and re-worked while it is still fresh.
The sheet is laid out to fit one page on both US Letter and A4. Leave the browser scaling at 100% and turn headers and footers off, and the 20 problems land inside the margins on either paper size.
Portrait orientation is what the sheet is designed for. Landscape works but wastes about a third of the paper, so leave the orientation alone unless you have a reason.
Print a sheet of 1st grade making 10 worksheets, run it for 8 minutes, mark it together, and come back tomorrow for a different set of numbers on the same skill.
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Free printable math worksheets from a working math academy director in Korea. Problems come from our own code, not from a published workbook. Every sheet prints on US Letter or A4 with its answer key. All worksheets · Worksheet generator · Korean site
Last updated: 2026-09-13