# Explain how to subtract related unit fractions

I can explain how to subtract related unit fractions

# Explain how to subtract related unit fractions

I can explain how to subtract related unit fractions

## Lesson details

### Key learning points

- Fractions need to have the same denominator if you are to subtract them.
- Common multiples help you to convert a fraction to a common denominator.
- The language of unitising helps you to subtract fractions with the same denominators.
- When subtracting fractions with the same denominators you just subtract the numerators.

### Common misconception

Pupils try to subtract the numerators and the denominators from one another for each fraction.

Represent each fraction using a model that draws out the equivalence of the fractions and the need for the same counting unit (denominator). Revisit previous analogies regarding sharing a common counting unit such as animals for cats and dogs.

### Keywords

Related fractions - When the denominator of one fraction is a multiple of the denominator of another fraction, we can say these fractions are related fractions.

Common denominator - When two or more fractions share the same denominator, you can say they have a common denominator.

### Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

## Video

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