How can your students work like mathematicians? In this book, helping students to develop as practising mathematicians, in addition to learning the mathematics, is the key principle. The authors have collected a number of engaging tasks which give students the opportunity to notice mathematical patterns and relationships, make conjectures, and justify and prove. The activities are broad enough to allow for differentiation through presenting mathematical situations that can be adapted and extended and encourage student choice. The tasks cover a wide range of topics that appear in secondary mathematics: functions; direct and inverse proportions; algebraic notation; fractions; powers and roots; circle theorems; quadratic and simultaneous equations; growth and decay; transformations; and more. To support using the tasks in the classroom, the book is accompanied by more than 100 downloadable whiteboard slides (for example, game grids, recording sheets, playing cards, isometric paper).