A companion to Aspects of Teaching Secondary Mathematics, this book introduces and explores the contemporary issues and key ideas entailed in the teaching and learning of this subject. This book is concerned with exploring the bigger picture of mathematics education, and is aimed particularly at those learning to teach mathematics; teachers in the classroom who want to continue thinking and developing as mathematics teachers; and those concerned with education who would like to be better informed about mathematics education. Divided into seven sections to help structure reading, this book offers a completely up-to-date, comprehensive overview, written by the most-known, well-respected experts in the field.