David Acheson is Emeritus Fellow of Jesus College, Oxford, and was the University's first winner of a National Teaching Fellowship in 2004. He was President of the Mathematical Association from 2010 to 2011, and now lectures widely on mathematics to young people and the general public. In 2013, Acheson was awarded an Honorary D.Sc. by the University of East Anglia for his outstanding work in the popularisation of mathematics. His books include 1089 and All That (OUP, 2002), The Calculus Story, (OUP, 2017), and The Wonder Book of Geometry, (OUP, 2020).

David Acheson captures the joy and wonder of mathematics in this little book, full of delightful and curious examples presented in a gentle, friendly way, yet packing in a number of profound ideas.

• 1: Introduction 2: Whatever Happened to A, B, and C? 3: The 1089 Trick 4: Another Kind of Magic 5: Just Imagine... 6: A Most Unusual Lecture 7: Why are Mathematicians Obsessed by Proof? 8: Puzzling Mathematics 9: Why Does (-1) × (-1) = +1? 10: It's a Square World 11: Algebra in Action 12: 'Compleating the Square' 13: Slices of Pi 14: The Golden Ratio 15: Proof by Chocolate 16: The Puzzled Farmer 17: Mathematics and Snooker 18: The Wicked Schoolteacher 19: Trains, Boats, and Planes 20: I've Seen That Before, Somewhere ... 21: An Apple Falls ... 22: Rollercoaster Mathematics 23: The Electric Guitar Revisited 24: The Domino Effect 25: Real or Imaginary? 26: The Square Root of Minus One 27: Inspector Riemann Investigates ... 28: Infinite Danger 29: 1 + 1 to the Rescue! 30: And Finally ... Notes and references Further Reading Index

David Acheson is Emeritus Fellow of Jesus College, Oxford, and was the University's first winner of a National Teaching Fellowship in 2004. He was President of the Mathematical Association from 2010 to 2011, and now lectures widely on mathematics to young people and the general public. In 2013, Acheson was awarded an Honorary D.Sc. by the University of East Anglia for his outstanding work in the popularisation of mathematics. His books include 1089 and All That (OUP, 2002), The Calculus Story, (OUP, 2017), and The Wonder Book of Geometry, (OUP, 2020).

David Acheson captures the joy and wonder of mathematics in this little book, full of delightful and curious examples presented in a gentle, friendly way, yet packing in a number of profound ideas.

• 1: Introduction 2: Whatever Happened to A, B, and C? 3: The 1089 Trick 4: Another Kind of Magic 5: Just Imagine... 6: A Most Unusual Lecture 7: Why are Mathematicians Obsessed by Proof? 8: Puzzling Mathematics 9: Why Does (-1) × (-1) = +1? 10: It's a Square World 11: Algebra in Action 12: 'Compleating the Square' 13: Slices of Pi 14: The Golden Ratio 15: Proof by Chocolate 16: The Puzzled Farmer 17: Mathematics and Snooker 18: The Wicked Schoolteacher 19: Trains, Boats, and Planes 20: I've Seen That Before, Somewhere ... 21: An Apple Falls ... 22: Rollercoaster Mathematics 23: The Electric Guitar Revisited 24: The Domino Effect 25: Real or Imaginary? 26: The Square Root of Minus One 27: Inspector Riemann Investigates ... 28: Infinite Danger 29: 1 + 1 to the Rescue! 30: And Finally ... Notes and references Further Reading Index

David Acheson is Emeritus Fellow of Jesus College, Oxford, and was the University's first winner of a National Teaching Fellowship in 2004. He was President of the Mathematical Association from 2010 to 2011, and now lectures widely on mathematics to young people and the general public. In 2013, Acheson was awarded an Honorary D.Sc. by the University of East Anglia for his outstanding work in the popularisation of mathematics. His books include 1089 and All That (OUP, 2002), The Calculus Story, (OUP, 2017), and The Wonder Book of Geometry, (OUP, 2020).

David Acheson captures the joy and wonder of mathematics in this little book, full of delightful and curious examples presented in a gentle, friendly way, yet packing in a number of profound ideas.

• 1: Introduction 2: Whatever Happened to A, B, and C? 3: The 1089 Trick 4: Another Kind of Magic 5: Just Imagine... 6: A Most Unusual Lecture 7: Why are Mathematicians Obsessed by Proof? 8: Puzzling Mathematics 9: Why Does (-1) × (-1) = +1? 10: It's a Square World 11: Algebra in Action 12: 'Compleating the Square' 13: Slices of Pi 14: The Golden Ratio 15: Proof by Chocolate 16: The Puzzled Farmer 17: Mathematics and Snooker 18: The Wicked Schoolteacher 19: Trains, Boats, and Planes 20: I've Seen That Before, Somewhere ... 21: An Apple Falls ... 22: Rollercoaster Mathematics 23: The Electric Guitar Revisited 24: The Domino Effect 25: Real or Imaginary? 26: The Square Root of Minus One 27: Inspector Riemann Investigates ... 28: Infinite Danger 29: 1 + 1 to the Rescue! 30: And Finally ... Notes and references Further Reading Index