This page makes free printable missing number subtraction worksheets on demand: press the button and you get a new sheet of 20 problems with a matching answer key, ready for US Letter or A4 paper. You will see items like □ − 2 = 7 and □ − 2 = 2 on the printed page, with 9 and 4 waiting on the answer key so nobody has to redo the arithmetic.
‘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 □ − 2 = 7 asks the child to work backwards, and that is a genuinely different skill from computing forwards. The answer 9 cannot be reached by reading left to right and doing what the sign says.
The sheet uses single-digit subtractions with one number hidden, so the difficulty is the reasoning, not the arithmetic.
These problems are the first real algebra a child meets. The empty box is a variable in everything but name, and children who are comfortable with □ − 2 = 2 tend to find equations far less strange two or three years later.
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.
These missing number subtraction worksheets are commonly aligned with the operations and algebraic thinking strand for this grade, and the skill appears in most curricula somewhere around this point.
| # | Problem | Answer | What to check |
|---|---|---|---|
| 1 | □ − 2 = 7 | 9 | Watch for: using the same operation instead of the inverse |
| 2 | □ − 2 = 2 | 4 | Check: guess-and-check without adjusting |
| 3 | □ − 2 = 3 | 5 | Look at: writing the whole equation as the answer |
| 4 | □ − 3 = 2 | 5 | Ask about: freezing when the box is first |
| 5 | □ − 7 = 1 | 8 | Watch for: treating the equals sign as 'the answer comes next' |
| 6 | 8 − □ = 5 | 3 | Check: ignoring the box and computing the two visible numbers |
Work □ − 3 = 2 out loud as a demonstration. It gives 5. Children who hear □ − 3 = 2 reasoned through once at the start of a session make noticeably fewer errors in the ten minutes that follow.
A good first problem to do together is □ − 2 = 7, which comes out at 9. Do □ − 2 = 7 once with the child narrating, then hand over the pencil and start the clock on the other 20 problems.
The answer key is generated with the worksheet, not written by hand, so it always matches the sheet in front of you — □ − 2 = 7 is listed as 9, □ − 2 = 2 as 4, and so on down the page.
Every generated sheet carries its own key on a separate printed page, which lets a child self-mark without seeing the answers while they work.
For a class set, print one sheet, press the new-worksheet button and print again. Each child gets different numbers on the same skill, so nobody can copy the answer to □ − 2 = 7 from a neighbour.
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.
When these become easy, move along the related links below rather than adding more problems to the same sheet.
→ Free Missing Number Worksheets
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