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

Starter quiz

Tick the equations that represent the image.
- ${4} \over {8}$ + ${1} \over {8}$ = ${5} \over {8}$ ✓
- ${4} \over {8}$ + ${1} \over {8}$ = ${5} \over {16}$
- ${1} \over {8}$ + ${4} \over {8}$ = ${5} \over {8}$ ✓
- ${1} \over {8}$ + ${4} \over {8}$ = ${5} \over {16}$
Tick the equation that represents the image (the cross indicates it has been subtracted).
- ${6} \over {12}$ − ${3} \over {12}$ = ${3} \over {12}$ ✓
- ${6} \over {12}$ − ${3} \over {12}$ = 3
- 6 − ${3} \over {12}$ = ${3} \over {12}$
- ${6} \over {12}$ − 3 = ${3} \over {12}$
Tick the fraction that is the simplest form of ${12} \over {14}$
- ${2} \over {4}$
- ${1} \over {7}$
- ${6} \over {7}$ ✓
- ${6} \over {14}$
Match the fraction to its simplest form.
- ${15} \over {20}$
  
  ⇔
  
  ${3} \over {4}$ ✓
- ${16} \over {30}$
  
  ⇔
  
  ${8} \over {15}$ ✓
- ${4} \over {12}$
  
  ⇔
  
  ${1} \over {3}$ ✓
- ${3} \over {21}$
  
  ⇔
  
  ${1} \over {7}$ ✓
Tick the options that could represent the sum: ${5} \over {12}$ + ${3} \over {12}$
- ${8} \over {24}$
- ${8} \over {12}$ ✓
- ${4} \over {6}$ ✓
- ${2} \over {3}$ ✓
- ${4} \over {12}$
Tick the options that could represent the difference: ${10} \over {15}$ − ${5} \over {15}$
- ${5} \over {15}$ ✓
- ${1} \over {5}$
- ${1} \over {3}$ ✓
- ${5} \over {30}$
- ${2} \over {10}$

Exit quiz

$What fraction of the shape is shaded?$

What fraction of the shape is shaded?
- ${7} \over {12}$ ✓
- ${5} \over {12}$
- ${1} \over {3}$
- ${1} \over {2}$
$What fraction of the shape is shaded?$

What fraction of the shape is shaded?
- ${1} \over {3}$
- ${1} \over {4}$ ✓
- ${3} \over {12}$ ✓
- ${3} \over {9}$
$What fraction of the shape is shaded?$

What fraction of the shape is shaded?
- ${4} \over {10}$ ✓
- ${1} \over {8}$
- ${4} \over {7}$
- ${2} \over {5}$ ✓
$What fraction of the whole shape is shaded?$

What fraction of the whole shape is shaded?
- ${7} \over {15}$ ✓
- ${3} \over {11}$
- ${7} \over {8}$
- ${1} \over {3}$
$What fraction of the whole shape is shaded?$

What fraction of the whole shape is shaded?
- ${2} \over {16}$
- ${6} \over {16}$ ✓
- ${3} \over {8}$ ✓
- ${1} \over {4}$
One-third of a garden patio is covered by a garden bench. Two twelfths of the garden patio is covered by a table. How much of the garden patio is covered?
- ${6} \over {12}$ ✓
- ${3} \over {36}$
- ${3} \over {15}$
- ${1} \over {2}$ ✓

Worksheet

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Presentation

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Lesson Details

Key learning points

Fractions need to have the same denominator if you are to add and subtract them.
Common denominators for non-related fractions can be found using common multiples of the denominators.
When adding or subtracting fractions with the same denominators you just add or subtract the numerators.

Common misconception

Pupils think that although parts look different, they cannot represent the same fraction of the whole.

Ensure multiple examples are provided where the fractional parts of the whole look different but instead are equivalent in value. You may like to create a concrete example of each shape and show how it can be manipulated so the parts are equivalent.

Keywords

Common denominator - When two or more fractions share the same denominator, you can say they have a common denominator.