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.

A fraction is in its simplest form when the numerator and denominator cannot be any smaller, while still being whole numbers.

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

Maths

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. 

Addition and subtraction of fractions

Tick the options that could represent the sum:   $${3} \over {12}$$ + $${3} \over {12}$$

Tick the options that could represent the sum:    $${9} \over {18}$$ − $${6} \over {18}$$

$${4} \over {8}$$ + $${12} \over {8}$$ = $${16} \over {8}$$

$${4} \over {8}$$ + $${12} \over {8}$$ = $$2 {4} \over {8}$$

$${4} \over {8}$$ + $${12} \over {8}$$ = $${16} \over {16}$$

$${4} \over {8}$$ + $${12} \over {8}$$ = $$2 {1} \over {8}$$

$${4} \over {8}$$ + $${12} \over {8}$$ = 2

$${18} \over {6}$$ − $${2} \over {6}$$ = 16

$${18} \over {6}$$ − $${2} \over {6}$$ = $${16} \over {6}$$

$${18} \over {6}$$ − $${2} \over {6}$$ = $$2 {8} \over {3}$$

$${18} \over {6}$$ − $${2} \over {6}$$ = $$2 {{2} \over {3}}$$

$${18} \over {6}$$ − $${2} \over {6}$$ = $$2 {{4} \over {6}}$$

Tick the sum in its simplest form. $${9} \over {12}$$ + $${7} \over {12}$$

Tick the difference in its simplest form.    $$ {24} \over {12}$$ − $$ {6} \over {12}$$

Select the correct answer. $${6} \over {10}$$ − $${3} \over {10}$$ = ___

Tick the options that could represent the sum: $${4} \over {7}$$ + $${5} \over {7}$$

Tick the options that could represent the difference:    $${15} \over {3}$$ − $${5} \over {3}$$

Tick the fractions in their simplest form.

Tick the correct symbol to compare these fractions.    $${4} \over {16}$$  ___  $${6} \over {21}$$

Order the following fractions from largest to smallest. 

Starter Quiz