Adding fractions with unlike denominators worksheets
Adding and subtracting fractions with different denominators by first rewriting them over a common denominator.
Download the free adding and subtracting fractions with unlike denominators worksheet (PDF)
Adding and subtracting fractions with unlike denominators worksheet
What’s on the worksheet
- 50 questions on adding and subtracting fractions with unlike denominators, sized for US Letter paper
- 3 pages of questions plus an answer key on the last page
- Written for grade 5, matching Common Core 5.NF.A.1
- Name and date lines at the top, and room to show the work
Preview the worksheet and answer key
Make a new adding and subtracting fractions with unlike denominators worksheet
Need another page for extra practice, a retake or a second group in class? The free Mathify Kids test maker builds a fresh adding and subtracting fractions with unlike denominators worksheet with different numbers every time. Choose Core, Standard or Challenge level, print it with its own answer key, or let your child take it on screen and see the score straight away.
Adding and subtracting fractions with unlike denominators: a worked example (1/3 + 1/4)
- Find a common denominator: the LCM of 3 and 4 is 12.
- Rewrite: 1/3 = 4/12 and 1/4 = 3/12.
- Add: 4/12 + 3/12 = 7/12.
How to use it at home and in class
At home
Make sure equivalent fractions are solid first. Every problem on this sheet depends on them. Ten problems a day works better than a whole sheet at once. Mark them together with the answer key, then ask your child to explain one they got wrong: finding the mistake themselves is where the learning happens.
In class
Use the first row as a warm-up, a full page for independent practice, or five questions as an exit ticket. For a retake or a second group, make a new version with the test maker so every child gets different numbers.
Mistakes to watch for
- Adding tops and bottoms straight across, so 1/3 + 1/4 becomes 2/7.
- Changing the denominator but not the numerator.
What to practice before and after adding and subtracting fractions with unlike denominators
- Before: adding and subtracting fractions with like denominators. If this sheet is a struggle, go back a step.
- Learn it first: the adding and subtracting fractions with unlike denominators lesson and the fractions chart.
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Questions parents ask
What is the easiest common denominator to use?
The least common multiple of the two denominators. Multiplying them together also works but gives bigger numbers to simplify.
What grade is this adding and subtracting fractions with unlike denominators worksheet for?
It is written for grade 5 and matches Common Core standard 5.NF.A.1.
Can I get a different version of this adding and subtracting fractions with unlike denominators worksheet?
Yes. Use the free Mathify Kids test maker to make a new adding and subtracting fractions with unlike denominators worksheet with different numbers every time, at Core, Standard or Challenge level, with its own answer key.