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

      I can use knowledge of fractions in their simplest form when solving addition and subtraction problems.

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      Lesson 3 of 10
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      • Year 6

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

      I can use knowledge of fractions in their simplest form when solving addition and subtraction problems.

      Lesson details

      Key learning points

      1. You divide the numerator and denominator by the same factor to create the equivalent fraction.
      2. A fraction is in its simplest form when there is no common factor of the numerator and the denominator.
      3. Fractions greater than 1 can be simplified in the same way.

      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.

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

      Common misconception

      Pupils think that any numerator and denominator can be divided by 2 even when the numerator or denominator is odd.

      Highlight to children that although it can sometimes be helpful to think of the magnitude of a fraction when the fraction is simplified with a decimal as the numerator or denominator, fractions can only be written with whole numbers.

      A pupil's ability to simplify a fraction is dependent on their times table knowledge and their understanding of factors. Should this be a challenge, remind pupils of the language of factors and provide a times table grid to support pupils to find the common factors of different numbers.
      Teacher tip

      Licence

      This content is © Oak National Academy Limited (2025), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

      Lesson video

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      Prior knowledge starter quiz

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      6 Questions

      Q1.
      Select the correct answer. $${6} \over {10}$$ − $${3} \over {10}$$ = ___

      Correct answer: $${3} \over {10}$$
      3
      $${9} \over {10}$$
      $${3} \over {5}$$

      Q2.
      Tick the options that could represent the sum: $${4} \over {7}$$ + $${5} \over {7}$$

      Correct answer: $${9} \over {7}$$
      $${7} \over {9}$$
      $${1} \over {7}$$
      $$1 {{2} \over {14}}$$
      Correct answer: $$1 {{2} \over {7}}$$

      Q3.
      Tick the options that could represent the difference: $${15} \over {3}$$ − $${5} \over {3}$$

      10
      Correct answer: $${10} \over {3}$$
      $${10} \over {6}$$
      $$1 {{2} \over {3}}$$
      Correct answer: $$3 {{1} \over {3}}$$

      Q4.
      Tick the fractions in their simplest form.

      $${4} \over {12}$$
      $${12} \over {15}$$
      Correct answer: $${1} \over {9}$$
      Correct answer: $${3} \over {7}$$

      Q5.
      Tick the correct symbol to compare these fractions. $${4} \over {16}$$ ___ $${6} \over {21}$$

      Correct answer: <
      >
      =

      Q6.
      Order the following fractions from largest to smallest.

      1 - $${4} \over {24}$$
      2 - $${5} \over {25}$$
      3 - $${3} \over {12}$$
      4 - $${6} \over {30}$$

      Assessment exit quiz

      Download quiz pdf

      6 Questions

      Q1.
      Tick the options that could represent the sum: $${3} \over {12}$$ + $${3} \over {12}$$

      $${6} \over {24}$$
      Correct answer: $${6} \over {12}$$
      $${3} \over {4}$$
      Correct answer: $${1} \over {2}$$

      Q2.
      Tick the options that could represent the sum: $${9} \over {18}$$ − $${6} \over {18}$$

      Correct answer: $${3} \over {18}$$
      3
      $${3} \over {0}$$
      Correct answer: $${1} \over {6}$$
      $${2} \over {12}$$

      Q3.
      Tick the equations that are true.

      Correct answer: $${4} \over {8}$$ + $${12} \over {8}$$ = $${16} \over {8}$$
      $${4} \over {8}$$ + $${12} \over {8}$$ = $$2 {4} \over {8}$$
      $${4} \over {8}$$ + $${12} \over {8}$$ = $${16} \over {16}$$
      $${4} \over {8}$$ + $${12} \over {8}$$ = $$2 {1} \over {8}$$
      Correct answer: $${4} \over {8}$$ + $${12} \over {8}$$ = 2

      Q4.
      Tick the equations that are true.

      $${18} \over {6}$$ − $${2} \over {6}$$ = 16
      Correct answer: $${18} \over {6}$$ − $${2} \over {6}$$ = $${16} \over {6}$$
      $${18} \over {6}$$ − $${2} \over {6}$$ = $$2 {8} \over {3}$$
      $${18} \over {6}$$ − $${2} \over {6}$$ = $$2 {{2} \over {3}}$$
      Correct answer: $${18} \over {6}$$ − $${2} \over {6}$$ = $$2 {{4} \over {6}}$$

      Q5.
      Tick the sum in its simplest form. $${9} \over {12}$$ + $${7} \over {12}$$

      $${16} \over {12}$$
      $$1 {{2} \over {6}}$$
      $${8} \over {12}$$
      $${8} \over {6}$$
      Correct answer: $$1 {{1} \over {3}}$$

      Q6.
      Tick the difference in its simplest form. $$ {24} \over {12}$$ − $$ {6} \over {12}$$

      $$ {18} \over {12}$$
      $$1 {{6} \over {12}}$$
      $$1 {{1} \over {6}}$$
      Correct answer: $$1 {{1} \over {2}}$$
      $$ {6} \over {4}$$

      Lesson appears in

      UnitMaths / Addition and subtraction of fractions

      Maths

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