This work comprises contributions from a broad range of countries and cultures; they are representative of different theoretical perspectives and classroom experiences. All contributors are concerned with helping teachers explore ways to develop children’s mathematical understanding appropriate for the new millennium. The authors present complex ideas about mathematical understanding and provide readers with powerful classroom examples. Recommendations for changing the curriculum for young children are also suggested. The book documents four years of development in the field. Among the emergent developments described is the importance of context to mathematical development - it is not only the physical context, but also the social context of the classroom and school that stimulate conceptual growth. The book also locates current theoretical perspectives in a broad framework. It is organized around four interconnected themes all related directly to teaching and learning mathematics.