This fully updated second edition synthesises the findings of the best of recent research from different parts of the world. Marilyn Nickson covers issues as diverse as pupils' understanding and handling of number, algebra, space and measurement, and their problem-solving ability, as well as the nature of assessment and the impact of ICT on the classroom. Each chapter provides both an overview of recent research and a detailed analysis of the most important findings. The research is carefully related to issues of pupils' progress in the subject, the differentiation of teaching, and the role of gender.