When we compare lists of factors of two or more numbers, common factors are those shared by all the numbers.

To simplify a fraction is to identify the highest common factor shared by the numerator and denominator and to scale down both by that factor.

If two numbers or expressions have the same value, they are said to be equivalent.

Reason about how to write a fraction in its simplest form

Maths

Explain how to write a fraction in its simplest form

Use knowledge of fractions in their simplest form when solving addition and subtraction problems

Explain how to add related unit fractions with a representation or image

Explain how to add related unit fractions without a representation or image

Explain how to subtract related unit fractions

Use knowledge of adding and subtracting related unit fractions to solve problems

Explain with and without an image how to add and subtract related non-unit fractions

Explain with and without images how to add and subtract related non-unit fractions bridging a whole

Add and subtract non-related fractions with different denominators

In this unit pupils will explain how to write a fraction in its simplest form when solving addition and subtraction problems and how to add and subtract related fractions. In the future unit pupils will use their fraction sense to fraction addition, subtraction and comparison explaining how to compare pairs of non-related fractions by converting to common denominators and using fraction sense.

In the prior unit pupils used representations to describe and compare two fractions. They explained the relationship within families of equivalent fractions and used their knowledge of common equivalents to compare fractions with decimals. In this unit pupils will explain how to write a fraction in its simplest form when solving addition and subtraction problems. 

In this unit pupils will explain how to write a fraction in its simplest form when solving addition and subtraction problems.

Addition and subtraction of fractions

Tick the fraction that is the simplest form of $${15} \over {20}$$

Match the equivalent fraction to its simplest form.

Tick the fractions in their simplest form.

Tick the correct symbol to compare these fractions.    $${4} \over {12}$$ ___ $${5} \over {15}$$

Tick the correct symbol to compare these fractions.    $${6} \over {15}$$ ___$${40} \over {100}$$

Order the following fractions from largest to smallest

Tick the highest common factor of 12 and 18

divide the numerator and denominator by a common factor.

divide the numerator and denominator by the highest common factor.

To find the simplest form of a fraction, we:

Tick the fraction that is the simplest form of $${8} \over {16}$$

Tick the fraction that is the simplest form of $${6} \over {8}$$

If $${2} \over {3}$$ is the simplest form of a fraction, tick the equivalent fractions.

Starter Quiz

Write down a common factor of 4 and 20