Thinking Mathematically is about mathematical processes, and not about any particular branch of mathematics. Our aim is to show how to make a start on any question, how to attack it effectively and how to learn from the experience. Time and effort spent studying these processes of enquiry are wisely invested because doing so can bring you closer to realizing your full potential for mathematical thinking. Experience in working with students of all ages has convinced us that mathematical thinking can be improved by ● tackling questions conscientiously; ● reflecting on this experience; ● linking feelings with action; ● studying the process of resolving problems; and ● noticing how what you learn fits in with your own experience. Consequently while encouraging you to tackle questions, we show you how to reflect on that experience by drawing your attention to important features of the process of thinking mathematically.