Ratio, proportion & rates of change · Ratio
Chapter 1 · 4
The idea
Sharing a quantity in a ratio
Why a ratio splits a quantity into equal "parts", how to find the value of one part, and how that unlocks difference, one-share-given, and fraction questions.
A full journey — read it, play with it, work it, then earn real exam marks. Everything stays on the timeline below.
In this lesson — start anywhere
Ratio, proportion & rates of change · Ratio
Sharing a quantity in a ratio
Why a ratio splits a quantity into equal "parts", how to find the value of one part, and how that unlocks difference, one-share-given, and fraction questions.
Why it works
A recipe for equal parts
A ratio like is not two amounts — it's a recipe for cutting something into equal parts. "Share £480 in the ratio " means: chop the £480 into equal parts, give one person of those parts and the other . So the single most useful move in every ratio question is:Find the part, and the whole question falls open.
Add the ratio numbers first
The commonest mistake is to divide by one of the ratio numbers — say — or by the number of people. Neither is the number of parts. There are parts, so you divide by . Miss the "add them up" step and every share is wrong.Keep reading — free
The rest of the explanation, plus 2 worked examples you step through move by move.
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