This book, which was first published in 1990, is aimed at teachers, mathematics educators and general readers who are interested in mathematics education from a psychological point of view. The book describes research findings that shed light on the learning of mathematics from early arithmetic to high levels of algebra and geometry. The book is the collaborative effort of a number of members of the International Group for the Psychology of Mathematics Education and primarily describes their work whilst at the same time covering many issues that interest researchers in mathematics education.
Chemists, working with only mortars and pestles, could not get very far unless they had mathematical models to explain what was happening "inside" of their elements of experience -- an example of what
