The present trend in English primary education is to have teachers who are not only class teachers but also subject specialists. The books in this new series are intended to support this specialist approach. Other volumes cover English, Geography, and Science, with Art and History forthcoming. In spite of more than 20 years of attempted reforms, many children still learn mathematics as a set of rules which they memorize and apply, with little understanding of the mathematical relationships on which these rules are based. The National Curriculum guidelines, on the other hand, emphasise knowledge, understanding and skills. This book fully supports that emphasis. Written by a mathematics teacher who also became a psychologist, it is the outcome of 30 years' research into the psychological principles which underlie the learning of mathematics with understanding. The book's main purpose is to provide teachers with a clear explanation of these principles, to explain the relation between understanding and skills, and to describe their application to the teaching of mathematics. The book contains numerous activities to show how mathematics may be learnt in the primary classroom with understanding and enjoyment.