����ý

Alan Davies and Marcus Du Sautoy get to grips with the problem of measuring the exact length of a piece of string. They visit the National Physics Laboratory, look at how a metre is defined now, and explore the history of measurement and standardisation along the way.

This is good reinforcement of the problem of measurement and bounds of measures. Students could try measuring their own pieces of string in different ways and with different units and compare their results. Use different scales of map to measure similar features and see if different levels of detail produce different results.