## Scaling – zoom: primary and secondary

The ‘zoom’ lens on a camera and a ‘zoom’ photocopier do mathematics. They perform a geometrical transformation: enlargement. We do the same in this workshop. We move up through the dimensions from 1, where we compare paper clips; through 2, where we use a pantograph and the technique artists call ‘squaring up’; to 3, where we begin with a ‘maquette’ and build a full-scale version.

When the length of something goes up by a certain scale factor, how does the surface area go up? How does the volume go up?

A formula encapsulates the answer, whether written as such by older students, or expressed in words by younger ones.