"This is an exquisitely interesting book. It's a deeply serious one too and, for those like me who have little maths, it's delightfully readable" - IAN MCEWAN "Kit Yates is a natural storyteller. Through fascinating stories and examples, he shows how maths is the beating heart of so much of modern life. An exciting new voice in the world of science communication" - MARCUS DU SAUTOY "Used wisely, mathematics can save your life. Used unwisely, it can ruin it. A lucid and enthralling account of why maths matters in everyone's life. A real eye-opener." - Prof Ian Stewart FRS, author of DO DICE PLAY GOD?

Maths is the story of the world around us, and the wisdom it gives us can be the difference between success and disaster. We are all doing maths all the time, from the way we communicate with each other to the way we travel, from how we work to how we relax. Many of us are aware of this. But few of us really appreciate the full power of maths - the extent to which its influence is not only in every office and every home, but also in every courtroom and hospital ward. In this eye-opening and extraordinary book, Yates explores the true stories of life-changing events in which the application - or misapplication - of mathematics has played a critical role: patients crippled by faulty genes and entrepreneurs bankrupted by faulty algorithms; innocent victims of miscarriages of justice and the unwitting victims of software glitches. We follow stories of investors who have lost fortunes and parents who have lost children, all because of mathematical misunderstandings. Along the way, Yates arms us with simple mathematical rules and tools that can help us make better decisions in our increasingly quantitative society. You will discover why it's always sensible to question a statistic, often vital to ask for a second opinion and sometimes surprisingly handy to stick to the 37% rule...