Through the use of the problem solving approach, writing and investigating hypotheses is introduced. There is optional material on primary and secondary data. Pupils will use line graphs to present data.

The materials address issues such as reliability of data, use of estimations and the use of mathematical models to represent a more complicated situation. There are two optional activities within the materials – the first which familiarises pupils with general population figures and allows them to explore the wealth of data available on the web and the second which uses sweets to form a simple model of population growth.