Numbers, Groups and Codes

Rating:
Summary: The most fascinating math book I've ever read.
Review: This a university-level math textbook, but it can be read by anyone with a high school-level knowledge of algebra. It covers subjects such as set theory, error-correcting codes, properties of prime numbers, and boolean algebra, and it's FUN!! I especially liked the section on congruence classes. To give an example: the authors explain why a number of the form 4k + 3 (k is an integer) can never be the sum of squares, and they give you the tools to discover your own odd facts such as that. A very well-written math book.