This dictionary explains all the mathematical terms that are likely to be encountered at primary level. The ability to understand the language of mathematics and express mathematical ideas is important from the beginning. Although some of the words at this level may seem simple and commonplace it is their very familiarity that can give rise to problems. Words when used in their mathematical sense have very precise meanings that may be different from their more familiar meanings. A clear grasp of these basic terms helps provide a solid foundation on which to build. While a rigorous approach to mathematical definitions is essential the emphasis here is on clarity and understanding and meanings are presented in a way that is interesting and stimulating as well as being accurate.