The UK National Curriculum is clear about the importance of reasoning and problem-solving in mathematics. Mastery and Depth in Primary Mathematics aims to support trainee and established teachers to embed mathematical thinking into their lessons. The authors focus on practical and actionable ways that primary teachers can develop their children’s mathematical thinking, reasoning and problem-solving: ideas which are at the heart of the UK National Curriculum. Covering a range of areas in mathematical thinking such as reasoning, problem-solving and pattern-spotting, as well as systematic and investigative thinking, each chapter provides clear examples of how teachers can make small, manageable ‘rich tweaks’ to their existing lessons to increase the opportunities for children to develop their mathematical thinking. Teachers will be able to dip into the book and find inspiration and ideas that they can use immediately and, importantly, develop a set of principles and skills which will enable them to take any mathematical activity and tweak it to develop their pupils’ thinking skills. This practical guide will be invaluable to all trainee teachers and early-career teachers that wish to enhance their primary mathematics teaching.