The proportion of something is its size in comparison to the size of another thing. For instance, if a cake had a mass of 1kg, and the fruit component was 300g, then the proportion of fruit to nonfruit would be 300:700 which would cancel down to 3:7.

An example of direct proportion would be that the number of apples is directly proportional to the number of boxes needed to store them. As one amount goes up, so does the other.

An example of inverse proportion would be that the faster you travel, the less time it takes to get there. As speed increases, the time needed to travel a fixed distance decreases.

Ratio and Proportion

Ten questions on ratio and proportion of the type you might find on a GCSE maths paper.

Reading scales

Reading scales and palcing numbers on a number line.

Direct and inverse proportion questions

Direct and inverse proportion problems with answers.

Video on y is directly proportional to x

Simple direct proportion video that lasts about 3 minutes where y is directly proportional to x. Find the constant of proportionality and then work out the problem from there.

Video on y is directly proportional to x squared

Direct proportion video where y is directly proportional to x squared. Find the constant of proportionality and then work out the problem from there.

Video on a problem of y is directly proportional to x squared

A problem where direct proportion is involved where y is directly proportional to x squared. Find the constant of proportionality and then work out the problem from there.

Extra practice of Direct and Indirect Proportion

Direct and inverse proportion problems with answers. Same questions as The other Direct and Indirect Proportion sheet but with different numbers to give practice.

Ratio and Best Buy

A couple of questions on ratio and best buy. There is a video on how to answer these questions so if you want to have a go and then watch the video, that might be useful.