DfE statement R8 · Ratio, proportion and rates of change
Ratios, fractions and linear functions
Ratios, fractions and linear functions is content statement R8 of the DfE GCSE mathematics subject content, in the ratio, proportion and rates of change area. It is on both tiers, and it is examined without a calculator. Below is what the specification actually requires, the 3 mistakes that cost marks on this topic most often, and practice questions written to the statement — original questions, not past papers.
What the specification says
The DfE subject content for GCSE mathematics states, verbatim: "Relate ratios to fractions and to linear functions." (statement R8). Every awarding organisation — Pearson Edexcel, AQA and OCR — must cover it, so the wording is the same whichever specification your school follows.
Tier
Both tiers. This statement is Foundation content, which means Higher students are examined on it too — Higher is Foundation plus more, never instead of it.
Calculator
This is non-calculator territory. Questions on it belong naturally on Paper 1, where written method is all you have — so practise it that way rather than with a calculator to hand.
Common mistakes
- Treating y = mx + c with c not zero as a proportional relationship. Only y = mx is proportional.
- Converting a ratio to a fraction using one part as the denominator rather than the total, when the context calls for a fraction of the whole.
- Reading the constant of proportionality off the graph as the y-intercept rather than as the gradient.
Sample questions (10 of 30)
Nearby statements
Questions people ask
Is ratios, fractions and linear functions on Foundation or Higher?
Both. It is Foundation content, so it can be asked on either tier.
Can I use a calculator for ratios, fractions and linear functions?
Not on Paper 1, which is where this normally appears. Paper 1 is non-calculator for both tiers and carries the same 80 marks as each of the other two papers.
What is the single most common mistake here?
Treating y = mx + c with c not zero as a proportional relationship. Only y = mx is proportional.
Are these past paper questions?
No. Every question is original, written to this DfE content statement and checked before publication. We do not host past papers or mark schemes.
Back to Ratio, proportion and rates of change at Foundation or at Higher.