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What are unit fractions?

What are unit fractions?
We explain what unit fractions are and why children need to understand the concept of unit fractions before moving onto more advanced fractions learning.
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What are unit fractions?

A unit fraction is a fraction where the numerator (top number) is 1 and the denominator (bottom number) is a whole number. All these fractions are unit fractions:

Children will first learn about unit fractions in Year 1, when they will be introduced to the concept of 'half' and 'quarter'. They may be asked to divide a shape into halves or quarters as follows:

In Year 2, they will need to find one half, one quarter and three quarters of shapes and sets of objects. They will also be introduced to how these fractions are written:

When finding a fraction of a number, such as 1/4 of 12, children in Year 3 are taught that they need to divide the number 12 by the denominator (bottom number) of the fraction.  So 1/4 of 12 is 12 ÷ 4, which equals 3.

This learning then moves onto finding fractions of quantities (such as 4/5 of 20 or 2/3 of 18, etc.) so it is important that children understand the concept of unit fractions and are able to calculate with them before moving onto this more advanced learning.