Ratio & Proportion

How quantities scale together — direct and inverse proportion, compound measures, and rates of change.

Direct & Inverse Proportion

When one quantity changes, the other follows — learn when they scale together and when they work against each other.

Compound Measures (Speed, Density, Pressure)

Two quantities combined into one measure — master the triangles and you can find any missing value.

Rates of Change & Gradients

How steeply a graph climbs or falls — and what that slope actually tells you about the real world.