This guidance report focuses on the teaching of mathematics to pupils in Key Stages 2 and 3. It is not intended to provide a comprehensive guide to mathematics teaching. We have made recommendations where there are research findings that schools can use to make a significant difference to pupils' learning, and have focused on the questions that appear to be most salient to practitioners. There are aspects of mathematics teaching not covered by this guidance. In these situations, teachers must draw on their knowledge of mathematics, professional experience and judgement, and assessment of their pupils' knowledge and understanding. The focus is on improving the quality of teaching. Excellent maths teaching requires good content knowledge, but this is not sufficient. Excellent teachers also know the ways in which pupils learn mathematics and the difficulties they are likely to encounter, and how mathematics can be most effectively taught. This guidance is aimed primarily at subject leaders, headteachers, and other staff with responsibility for leading improvements in mathematics teaching in primary and secondary schools. Classroom teachers and teaching assistants will also find this guidance useful as a resource to aid their day-to-day teaching. [For the related evidence review, see ED612295. For the companion report, "Improving Mathematics in the Early Years and Key Stage 1. Guidance Report," see ED612298.]