Whether you paid much attention to the mathematics you were taught at school or not, the inescapable truth is that one day, an equation could just save your life. The real world is full of equations and a lot of our everyday decisions are calculated – we just don’t always realize it. And that’s ok – you unthinkingly use differentiation when you’re crossing the road between traffic and you will pretty much always make it to the other side safely. But what if you were plummeting to your death in a plane with no engine and you needed to know what size parachute to make from your cabinmate’s sari in order to jump and survive? Or you were in charge of pinpointing the origins of an important message from outer space? These entirely plausible real-life situations clearly require a little more thought. From how to work out the best guard configuration to protect a world-famous painting in the Louvre to saving the planet from total blackout during an energy crisis, Chris Waring demonstrates the mind-bending and humanity-saving beauty of equations.