Now in its ninth edition, this book helps equip teachers with the necessary skills, strategies, and activities that are essential for them to have when they are in their own elementary math classes. It incorporates the latest NCTM Curriculum Focal Points as well as the latest guidelines from professional organizations, such as the Guidelines for Assessment and Instruction in Statistics. The In the Classroom feature now includes masters of materials, games boards, and more on the accompanying Web site. Examples of authentic artifacts from real classrooms with analysis questions are presented. A new chapter on number theory is also included for teachers, which examines topics that are now emphasized in many of the states' standards for elementary students.