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Year 8

Direct proportion in context

I can recognise direct proportion in a range of contexts, including compound measures.

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New
New
Year 8

Direct proportion in context

I can recognise direct proportion in a range of contexts, including compound measures.

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These resources will be removed by end of Summer Term 2025.

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Lesson details

Key learning points

  1. Direct proportion can be used in a number of contexts.
  2. One context is converting compound measure.
  3. Another context is currency conversion.
  4. It is useful to be able to recognise which contexts involve direct proportion.

Keywords

  • Proportion - Two variables are in direct proportion if they have a constant multiplicative relationship.

Common misconception

Assuming that to convert 1 metre squared to cm squared you multiply by 100 and not 10 000

Encourage any pupil who initially finds this challenging to ensure that the values are in the required unit for the answer before doing the calculation.


To help you plan your year 8 maths lesson on: Direct proportion in context, download all teaching resources for free and adapt to suit your pupils' needs...

Pupils can be provided with or research recipes they are interested in and scale the recipes to have the amounts needed to feed the class.
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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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6 Questions

Q1.
Graphs showing direct proportion have a gradient with an intercept of 0.
Correct Answer: positive
Q2.
Which of the following graphs does NOT show direct proportion?
An image in a quiz
An image in a quiz
An image in a quiz
Correct Answer: An image in a quiz
An image in a quiz
Q3.
Which tables show that A and B are in direct proportion?
Correct Answer: An image in a quiz
An image in a quiz
An image in a quiz
Correct Answer: An image in a quiz
An image in a quiz
An image in a quiz
Q4.
The constant of proportionality represented by this graph is .
An image in a quiz
Correct Answer: 2, two
Q5.
Which of the following is NOT true of this graph?
An image in a quiz
The constant of proportionality is 0.5
Correct answer: The gradient of the line is 2
Correct answer: The constant of proportionality is 2
The graph does show a directly proportional relationship.
Correct answer: The graph does not show a constant positive gradient.
Q6.
What are the missing words in this statement? A graph representing direct __________ has a __________ __________ gradient and an __________ of __________.
relationship, constant positive, intercept, one
proportion, changing positive, intercept, zero
Correct answer: proportion, constant positive, intercept, zero
proportion, constant negative, intercept, zero
relationship, constant negative, intercept, one

6 Questions

Q1.
Two variables are in proportion if they have a constant multiplicative relationship.
Correct Answer: direct
Q2.
5 miles = 8 kilometres. So 7 miles is kilometres.
Correct Answer: 11.2, 11.2km, 11.2 km, 11.2 kilometres
Q3.
Convert 1 m² into cm².
100 cm²
1000 cm²
Correct answer: 10 000 cm²
100 000 cm²
1 000 000 cm²
Q4.
The cost of a box of pens is £4.50. Five boxes of pens cost £ .
Correct Answer: 22.50, £22.50, £22.5, 22.5, £ 22.50
Q5.
If $20 = £15.80, which of the following are true?
Correct answer: $10 = £7.90
Correct answer: $100 = £79
$50 = £45.80
$8 = £3.80
Correct answer: $200 = £158
Q6.
A recipe needs 180 ml of milk to make 15 scones. You can make scones using 6 litres of milk.
Correct Answer: 500