Help with adding/ subtracting fractions

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Adding and subtracting fractions is typically introduced in 4th Grade and is limited to fractions with like denominators. In 5th Grade students then move on and use equivalent fractions to help add and subtract fractions that have different denominators.

The following information and resources will help your child with adding and subtracting fractions.

Adding or subtracting fractions – same denominator

Encourage your child to start adding and subtracting fractions with the same denominator before trying to work with fractions with different denominators.

Adding or subtracting fractions – different denominator

Be sure your child understands equivalent fractions before tackling adding or subtracting fractions.

Adding and subtracting fractions requires fractions with unlike denominators to be changed so that all fractions have the same denominator.

Fraction Lesson: Adding and Subtracting Fractions

This short lesson shows how to add and subtract fractions.

The above lesson includes audio (so remember to switch on your speakers). Use the play/ pause button if you need to stop and start the lesson.

Related Fractions Lessons


worksheet generator iconTry the fraction worksheet generator. It provides limitless questions on adding and subtracting fractions.

The steps shown in the above lesson are also shown below using two fractions: 3/4 and 5/6.

Worked example showing finding fractions with common denominators for two fractions (3/4 and 5/6 becoming 9/12 and 10/12)

Adding or subtracting mixed numbers

There are two methods of adding or subtracting mixed numbers. Either add the whole numbers and then add the fraction parts, or convert each mixed number to an improper fraction before calculating. remind your child to reduce any answers to their lowest term and to change any improper fractions to mixed numbers.

Tips and Reminders

When adding/ subtracting mixed numbers:

  • Add the whole number parts.
  • Change the fractions as required to their equivalent values so all fractions have the same denominator.
  • Add/ subtract the numerators. Leave the denominator as is.

The example below shows the adding of two mixed numbers.

Illustration showing the addition of two mixed number (2 1/3 and 3 3/4)

Note: An alternative to the above method involves changing the mixed numbers to improper fractions (7/3 and 15/4), converting these to equivalent values (28/12 and 45/12), adding these, and finally changing the improper fraction to a mixed number.

Worksheets – adding, subtracting fractions

Use the worksheets below to practice adding and subtracting fractions

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