The international best-seller that makes mathematics a thrilling exploration. In twelve dreams, robert, a boy who hates math, meets a number devil, who leads him to discover the amazing world of numbers: infinite numbers...The international best-seller that makes mathematics a thrilling exploration. In twelve dreams, robert, a boy who hates math, meets a number devil, who leads him to discover the amazing world of numbers: infinite numbers, prime numbers, fibonacci numbers, numbers that magically appear in triangles, and numbers that expand without.