The Open University has developed a model (Calculators in the primary school) which identifies two components in the mathematics curriculum. First there are lessons in which specific techniques or concepts are learned. Second, whether in mathematics lessons or in other subjects, opportunities arise for techiques to be used (often through some form of problem solving). The point is made that these two aspects are interdependent; the learning of techniques paves the way for future application, while the using of techniques provides a purpose for the learning of mathematical ideas.