ABSTRACT
Relations are the stuff of mathematical development. Children must learn what it means to say that two numbers are equal or that one is more than the other. They have eventually to learn to deal with part-part relations (ratios) and with part-whole relations (fractions, for example). They must be able to co-ordinate separate relational judgements in order to measure and understand measurement (A=B, B=C, therefore A=C) and to understand an ordinal series (A>B, B>C, therefore A>C) properly. They have to learn about multiplicative relations. On top of all this they have to learn about the connections between these different relationships, if they are to acquire a coherent picture of the mathematics that they are taught at school and the mathematics that they use in their everyday life.
