Common Denominator Worksheets

Teaching notes for parents and teachers

How to teach it

Partition both strips into pieces of the same size. Record the new numerator as well as the new denominator.

Ask your student

How many new pieces replace each original piece?

If your student needs help

If the student changes only the denominator, count the shaded pieces in the new partition.

Choosing and using the worksheet

Each question pairs a proper fraction with denominator 2 through 9 and a unit fraction whose denominator is one greater. For example, a denominator of 5 is paired with a denominator of 6. The least common denominators range from 6 through 90. These consecutive denominators have no shared factor greater than one, so their product is the least common denominator. Do not assume that multiplying the denominators always gives the least one: for 4 and 6, the product is 24 but the least common denominator is 12.

Make a practice set

Select the worksheet, answer key, or both. When both are selected, the answer key prints after the questions. Keep it separate if you want your student to work independently.

After your student finishes

Before adding fractions with unlike denominators, ask the child to explain why both fractions keep their value when renamed. Check both answers, then use like-denominator addition to practice combining equal-sized parts.

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  Calculation practice

  Adding Fractions With Like Denominators

  Add equal-sized parts; simplify sums that may be greater than one.

  12 problems · Answer key included
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  Calculation practice

  Simplifying Fractions

  Divide both numbers by a common factor while keeping the fraction value unchanged.

  6 problems · Answer key included

More about fractions · Grade 5 worksheets

Grade 5 selected skill connection: 5.NF.A.1 prerequisite: common denominators. See the Common Core standards for this grade. This worksheet does not cover every requirement in the standard.