Random numbers are immensely important in scientific research, in economic decision making, in polling, gaming, and cryptography and algorithm design. Surprisingly, while many popular books in mathematics have been written about prime numbers, about , e, √-1, there exist no books for the general reader about random numbers. True, the subject of randomness as such has been the subject of several books, but random numbers are only mentioned, if at all, as a by-product. Given the immense theoretical and practical importance of random numbers, this is astonishing. This book proposes to fill that gap. The book discusses random numbers under five headings: What are they? What are they good for? How do we produce them? Why do we need them? How do we fake them? The book has been written with a sophisticated general reader in mind, but should be of much interest to students and academics of all levels who have an interest in mathematics and randomness. Features · Written in an easily readable, conversational style · Aimed at general readers who are interested in mathematics in general, or who have read books about , e, √-1, or irrational numbers · Accessible to anybody with a high-school mathematics education.