What Is A Unit Fraction? Explained For Primary Schools

In this post we will be explaining what a unit fraction is, what they mean, and providing you with some questions you can use to test your KS2 students’ skills when it comes to unit fractions.

What is a unit fraction?

A unit fraction is any fraction with 1 as its numerator (top number), and a whole number for the denominator (bottom number). 

Examples of unit fractions include:

Examples of unit fractions
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Understanding and Comparing Fractions Worksheets

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When will my child learn about unit fractions?

Although the terminology of ‘unit fraction’ is not yet introduced, Year 1 pupils should: 

  • recognise, find and name a half as one of two equal parts of an object, shape or quantity; 
  • recognise, find and name a quarter as one of four equal parts of an object, shape or quantity.
Unit fractions for year 1 pupils

In Year 2, pupils use fractions as ‘fractions of’ discrete (whole numbers) and continuous (any numerical value e.g. 3.6) quantities by solving problems using shapes, objects and quantities. 

They connect unit fractions to:

  • equal sharing and grouping; 
  • to numbers when they can be calculated;
  • and to measures, finding fractions of lengths, quantities, sets of objects or shapes. 

They also meet 3/4 as the first example of a non-unit fraction.

Unit fraction slide for year 2 pupils on Third Space's online intervention
One of the unit fraction lessons for Year 2 on Third Space Learning’s online intervention.

Year 3 pupils should: 

  • recognise, find and write fractions of a discrete set of objects: unit fractions and non-unit fractions with small denominators; 
  • recognise and use fractions as numbers: unit fractions and non-unit fractions with small denominators; 
  • compare and order unit fractions, and fractions with the same denominators;
  • begin to understand unit and non-unit fractions as numbers on the number line, and deduce relations between them, such as size and equivalence; 
  • understand the relation between unit fractions as operators (fractions of), and division by integers; 
  • continue to recognise fractions in the context of parts of a whole, numbers, measurements, a shape, and unit fractions as a division of a quantity.
Unit and non unit fractions on a number line

Unit fractions are then not mentioned in the curriculum until Year 6, where pupils use their understanding of the relationship between unit fractions and division to work backwards by multiplying a quantity that represents a unit fraction to find the whole quantity (for example, if 1/4 of a length is 36cm, then the whole length is 36 × 4 = 144cm).

Read more: How To Multiply Fractions: Step By Step Guide

Wondering about how to explain other key maths vocabulary to your children? Check out our Primary Maths Dictionary, or try these other terms related to unit fractions:

Unit fraction practice questions for primary school children

1) Write these numbers in order, starting with the smallest: 1/2, 1/4, 1/8, 1/5

2) Circle the biggest unit fraction: 1/6, 1/4, 1/3, 1/5

3) Shade in 1/5 of this shape (you can recreate this on a piece of paper): 

Unit fraction question

4) Calculate 1/7 of 21.

Further reading:
Third Space Learning Upsell Section


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20+ worded problems to extend your pupils’ reasoning skills using percentages and decimals, from Years 3-6.

10 questions for each year group of ascending difficulty, and a challenge question to stretch pupils beyond the core understanding of percentages and decimals and on to mastery.

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