This book brings together current research on the use of mathematics curriculum materials by teachers and the impact of curriculum materials on teaching and teachers, with particular emphasis on, but not limited to, materials developed in the 1990s in response to NCTM principles and school math standardsDespite the enormous amount of curriculum development activity over the past 15 years and the growing interest of the Academy in its use, the book is the first collection of research on curriculum materials for mathematics, mathematics and the first volume with this focus in any content area in several decades.