Alex's Adventures in Numberland, By Alex Bellos

Gratifyingly for those of us who are not too hot on numbers, Alex Bellos begins this unexpectedly beguiling exploration with an Amazonian tribe called Munduruku who scarcely bother with them at all. Ask a father of six how many children he has and the response is, "I don't know."

Numbers only appeared 10,000 years ago and were regarded with suspicion. After holding a census, King David was punished with three days of pestilence and 77,000 deaths. Those of us who still use our fingers for calculations are continuing a long tradition. In both Russian and Sanskrit, the words for five and hand are virtually the same. By using finger joints, the Chinese can count up to one number less than 10 billion. A tribe in Papua utilises the whole body for counting. The left testicle is 31. The 60-minute hour of the Babylonians still holds sway around the world despite attempts at introducing a 10-hour day after the French revolution and, more recently, a day divided into 1,000 "beats" of one minute 24.6 seconds by Swatch.

Bellos reminds us that Leibniz urged adoption of the binary system in the 17th century. In his discussion of the enigmatic, limitless and invaluable number pi, he visits the Chudnovsky brothers who worked it out to two billion decimal places on a home-made super-computer. Their feat was recently overtaken by Frenchman Fabrice Ballard, who calculated almost 2.7 trillion decimal places on his desktop PC. Even this devotion was surpassed by Akira Haraguchi, who publicly recited 100,000 decimal places in Tokyo a few years ago.

Originally used to solve a teaser about reproduction in rabbits, the Fibonacci sequence (0,1,1,3,5, 8, 13...) applies to pineapples, sunflowers, pine cones and explains why a four-leaf clover is an extreme rarity. The related golden ratio (1:1.618) is found in the pentagram, the swoop of a peregrine, the design of an iPhone.

Moving on to a more lucrative field, Bellow explains that we will lose an average of 52.6p per every £10 wagered on roulette ("a very efficient money-making machine"), but this goes down to 14.1p if we switch to craps.

Bellos's wonderfully engaging book is a joy in every aspect except the clunky title. He should have taken the advice of the American numerologist who also told Puff Daddy to become P.Diddy: "One of the greatest men who walked this earth was not called Alex the Great."