This is a fully revised and updated edition of the authors successful and much-used book. It is written for those who teach mathematics, for those who are preparing to teach mathematics to children aged 3 to 8 years, as well as for those who wish to have a clearer understanding of the mathematical ideas behind the material they use in the classroom. This book also shows how children can be helped to develop an understanding of mathematics for themselves. The revisions introduced in the Second Edition reflect recent changes such as the Early Learning Goals for the Foundation Stage and the particular emphasis of The National Numeracy Strategy. Sections on addition and subtraction, multiplication and division have been revised, and the book includes coverage of mental calculation strategies. This is an essential student text and professional reference work for teachers of children aged 3 to 8 years.