## Humble Pi

**** Sunday Times #1 Bestseller ****

Why can’t smart phones divide 75 by 14? How come Excel has difficulty calculating that 0.5 – 0.4 – 0.1 = 0? Why do spreadsheets fail after row 1,048,576? More seriously, perhaps, why do US jet fighters have a tendency to go wrong when they cross the international date line? How did the ancient Greeks get themselves in a fix moving stone pillars from one building site to another? Why was a British woman was convicted of murder on the basis of a statistician for the prosecution working out that the chance of her being innocent was 0.00000014%, when the actual chance was 89%? And why should you never trust a mathematician who invites you to wager on the outcome of a series of coin-tosses?

At an abstract level, the subject of mathematics itself is, by definition, never wrong. Mathematics is the pursuit of pure correct logic. Humans, on the other hand, are great at getting things wrong.

*Humble Pi* is a history of mathematical error, misapplication and failure. Along the way, it also shows us why maths is a fantastic ally, and how it can make up for our inadequacies, and allow us to access logic and reasoning we cannot grasp intuitively.