Mathematics teaching materials

Everyday Graphs

Written by Richard Phillips; Shell Centre, 1990.

Everyday Graphs
Price in UK pounds: £10.

Everyday Graphs This is a collection of graphs to challenge the interpretation skills of pupils and their teachers. All the graphs have a number of things in common -

• All are graphs of real data - none have been invented.
• The graphs depict familiar, everyday events viewed in an unfamiliar way.
• All the data were collected with the aid of a computer.

Some of the graphs are much easier to understand than others: primary school children have tackled some of the easier ones.

Here is an example page.

This graph shows the temperature variations in a domestic hot water tank. Two temperature sensors were attached to the tank: one near the top and one near the bottom. The graph shows a 24 hour period starting and ending at midnight.

The tank is of the type normally found in a house in the UK. Cold water enters it at the bottom and hot water is drawn off from the top whenever someone uses a hot tap. Twice a day the water is heated by the central heating boiler the tank is lagged to reduce heat loss.

• At what times was the water being heated up?
• What was the first time that someone ran a hot tap?
• When was the most hot water being used?
• Why does the bottom graph vary so much more than the top graph?