This text has two major purposes. One is diagnostic-to aid in discerning a child's stage of development as a basic for determining the type of mathematics for which he is ready. The second major purpose is to serve the "methods of teaching mathematics" courses in teacher education.l The reader will find this book very different from other methods texts because it is based on how children learn, not how to teach, and it should enable readers to see mathematics from the standpoint of the child as he progresses through the various stages of development.