This article for teachers describes how modelling number properties
involving multiplication using an array of objects not only allows
children to represent their thinking with concrete materials,. . . .
Imagine you were given the chance to win some money... and imagine
you had nothing to lose...
Does changing the order of transformations always/sometimes/never
produce the same transformation?
An introduction to groups using transformations, following on from the October 2006 Stage 3 problems.