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Year 3MathsKS2

Unit FractionsYear 3 Lesson Plan

National Curriculum: Mathematics — Number: fractions, Year 3

Overview

Pupils develop their understanding of unit fractions (fractions with a numerator of 1) as equal parts of a whole or a set. They learn to read, write, and compare unit fractions, and begin to understand that as the denominator increases, the size of the fraction decreases.

Learning Objectives

  • Read and write unit fractions using correct notation.
  • Explain that a unit fraction is one equal part of a whole.
  • Compare unit fractions and order them on a number line.
  • Recognise that a larger denominator means a smaller fraction.

Key Vocabulary

fraction
A number that represents part of a whole or part of a set.
unit fraction
A fraction with a numerator of 1, e.g. ½, ⅓, ¼.
numerator
The top number in a fraction, showing how many parts are being considered.
denominator
The bottom number in a fraction, showing how many equal parts the whole is divided into.
equal parts
Parts that are the same size.
whole
A complete amount, not divided.

Suggested Lesson Structure

10m
Starter

Fold and shade paper strips into halves, thirds, and quarters. Ask: which piece is biggest? Which is smallest? Begin to connect size of piece to the denominator.

20m
Teaching input

Introduce fraction notation with numerator and denominator. Model unit fractions on a number line from 0 to 1. Compare ½ and ¼ using paper strips — establish that ½ > ¼ even though 4 > 2. Build understanding: more equal parts = smaller each part.

15m
Guided practice

Pupils shade unit fractions of shapes, place unit fractions on a number line, and write the fraction shown by a shaded diagram. Discuss: put ½, ⅓, ¼, ⅕ in order — which is largest?

10m
Independent practice

Pupils complete a differentiated activity: ordering unit fractions, shading fractions of shapes and sets, and a reasoning task ('Mia says ⅛ is bigger than ¼ because 8 is bigger than 4. Is she right?').

5m
Plenary

Which is bigger: 1/10 or 1/3? Pupils explain their reasoning using what they know about denominators.

Common Misconceptions

  • Pupils commonly believe that a larger denominator means a larger fraction — use practical materials to challenge this.
  • Confusion between the numerator and denominator — regularly use the language 'out of' to reinforce denominator meaning.

Prior Knowledge

Pupils should already be able to:

  • Ability to recognise halves and quarters from KS1.
  • Understanding of equal sharing.
  • Familiarity with number lines to 10 or 20.

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