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Year 6

Reason about how to write a fraction in its simplest form

I can reason about how to write a fraction in its simplest form.

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New
New
Year 6

Reason about how to write a fraction in its simplest form

I can reason about how to write a fraction in its simplest form.

Download all resources
Share activities with pupils

Lesson details

Key learning points

  1. A common factor is a number which is a factor of both the numerator and denominator.
  2. A fraction is in its simplest form when there is no common factor of the numerator and the denominator.

Common misconception

Pupils try to make a fraction in a simpler form by finding separate factors for the numerator and denominator to simplify.

Share examples for why this cannot be true with images to highlight the difference in the size of the fractions. Draw attention to the fact that it is both the numerator and denominator that needs to be scaled by a common factor.

Keywords

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

  • Simplify - 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.

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

Encourage children to recognise that where the denominator is a prime number and the fraction is a proper fraction, the fraction cannot be simplified any further as it has no other factors than one and itself.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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Starter quiz

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6 Questions

Q1.
Write down a common factor of 4 and 20
Correct Answer: 4, 2, 1
Q2.
Tick the highest common factor of 12 and 18
2
3
Correct answer: 6
12
Q3.
To find the simplest form of a fraction, we:
divide the numerator and denominator by a common factor.
make the numerator 1
make the fraction as small as we can.
Correct answer: divide the numerator and denominator by the highest common factor.
Q4.
Tick the fraction that is the simplest form of $${8} \over {16}$$
$${2} \over {8}$$
$${1} \over {8}$$
$${1} \over {16}$$
Correct answer: $${1} \over {2}$$
Q5.
Tick the fraction that is the simplest form of $${6} \over {8}$$
$${1} \over {8}$$
Correct answer: $${3} \over {4}$$
$${2} \over {4}$$
$${1} \over {6}$$
Q6.
If $${2} \over {3}$$ is the simplest form of a fraction, tick the equivalent fractions.
Correct answer: $${4} \over {6}$$
$${4} \over {12}$$
Correct answer: $${8} \over {12}$$
$${8} \over {9}$$

Exit quiz

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6 Questions

Q1.
Tick the fraction that is the simplest form of $${15} \over {20}$$
$${1} \over {20}$$
$${5} \over {4}$$
Correct answer: $${3} \over {4}$$
$${1} \over {4}$$
Q2.
Match the equivalent fraction to its simplest form.
Correct Answer:$${1} \over {3}$$,$${3} \over {9}$$

$${3} \over {9}$$

Correct Answer:$${1} \over {4}$$ , $${2} \over {8}$$

$${2} \over {8}$$

Correct Answer:$${1} \over {5}$$,$${3} \over {15}$$

$${3} \over {15}$$

Correct Answer:$${1} \over {6}$$,$${5} \over {30}$$

$${5} \over {30}$$

Q3.
Tick the fractions in their simplest form.
Correct answer: $${1} \over {3}$$
$${5} \over {5}$$
Correct answer: $${7} \over {8}$$
$${2} \over {12}$$
$${5} \over {25}$$
Q4.
Tick the correct symbol to compare these fractions. $${4} \over {12}$$ ___ $${5} \over {15}$$
<
>
Correct answer: =
Q5.
Tick the correct symbol to compare these fractions. $${6} \over {15}$$ ___$${40} \over {100}$$
<
>
Correct answer: =
Q6.
Order the following fractions from largest to smallest
1 - $${6} \over {18}$$
2 - $${8} \over {32}$$
3 - $${9} \over {45}$$
4 - $${7} \over {42}$$