These subtracting fractions with unlike denominators 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 3/8 − 1/3 and 4/5 − 1/3; the key lists 1/24 and 7/15 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.
Every step is visible on the page: rewrite, add, simplify. Children who try to do the rewriting in their heads make far more errors than those who write both new fractions down.
Adding fractions with different denominators is the first arithmetic that requires a preparation step. Before 3/8 − 1/3 can be added at all, the two fractions have to be rewritten over a common denominator — only then does 1/24 appear.
The generator produces unlike pairs every time, including pairs where one denominator is a multiple of the other — worth spotting in 2/7 − 1/6, because it halves the work.
Checking is possible by estimation: each fraction is roughly a half, a bit more or a bit less, and the answer to 4/5 − 1/3 should be in the neighbourhood the estimate suggests.
These subtracting fractions with unlike denominators worksheets are commonly aligned with the fractions strand for grade 5, and the skill appears in most curricula somewhere around this point.
| # | Problem | Answer | What to check |
|---|---|---|---|
| 1 | 3/8 − 1/3 = | 1/24 | Watch for: multiplying only one fraction up |
| 2 | 4/5 − 1/3 = | 7/15 | Check: finding a common denominator but forgetting the numerators |
| 3 | 2/7 − 1/6 = | 5/42 | Look at: using the product when a much smaller common denominator exists |
| 4 | 6/7 − 2/3 = | 4/21 | Ask about: subtracting the larger numerator from the smaller after conversion |
| 5 | 6/7 − 3/4 = | 3/28 | Watch for: stopping before simplifying |
| 6 | 3/7 − 1/3 = | 2/21 | Check: adding numerators and denominators straight across |
A good first problem to do together is 3/8 − 1/3, which comes out at 1/24. Do 3/8 − 1/3 once with the child narrating, then hand over the pencil and start the clock on the other 20 problems.
Work 6/7 − 2/3 out loud as a demonstration. It gives 4/21. Children who hear 6/7 − 2/3 reasoned through once at the start of a session make noticeably fewer errors in the ten minutes that follow.
The key prints on its own page by default. Uncheck the answer-key box before printing if you would rather keep it back and mark the sheet yourself.
The answer key is generated with the worksheet, not written by hand, so it always matches the sheet in front of you — 3/8 − 1/3 is listed as 1/24, 4/5 − 1/3 as 7/15, and so on down the page.
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 3/8 − 1/3 from a neighbour.
Printing works the same on US Letter and A4, because the layout uses relative widths rather than fixed inches. Set margins to default and scaling to 100%, and all 20 problems fit.
Keep the finished subtracting fractions with unlike denominators worksheets in date order — the drop in time across ten sheets is the clearest progress report you will get.
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