The Glorious Golden Ratio by Alfred S. Posamentier.  2012, ISBN 978-1-61614-423-4. If you are interested in Mathematics then you'll love this book. The golden ratio is a number which occurs in geometry over and over again. The golden ratio is also related to the Fibonacci and Lucas numbers. This book discusses how to construct the golden ratio, how it has been used in the past and gives many examples of it in geometry. Purchased at Powells books, on 1-21-2012, for $27.00.

The Man of Numbers by Keith Devlin. 2011, ISBN 978-0-8027-7812-3. Subtitled: Fibonacci's Arithmetic Revolution. This book is about Leonardo of Pisa aka Fibonacci. The book is well written. However, not much is known about Fibonacci, so it is a bit thin. The book describes Fibonacci's contribution to the western world as one of making the Hindu-Arabic number system more available to merchants and bankers in medieval Italy. Fibonacci did this through his book Liber Abbaci (the Book of Calculation). The book introduces the Hindu-Arabic numbers and how to do calculations with them. It does this mostly by presenting story problems that would be easy to understand or were relevant to the merchants of that time. The book also introduces algebraic ideas concerning how to solve story problems. Today the name Fibonacci is associated with Fibonacci Numbers. This because this number sequence appears in Liber Abbaci (see page 404, Liber Abaci, translated by L. E. Sigler) in a story about rabbits. The story, like the many other stories in the book, is intended as a way to use the number system to do math problems and not as a treatise on rabbit biology (or Fibonacci numbers either.) Purchased at Powell's books, 9-6-2011 for $25.00.

The Fabulous Fibonacci Numbers by Alfred S. Posamentier and Ingmar Lehmann. 2007, ISBN 978-1-59102-475-0.
This book discusses the Fibonacci numbers. It gives some of their history and many of the areas of mathematics and science that are touched by this number series. Also, discusses the Lucas numbers and the Golden Ratio. If you enjoy mathematics and numbers then you'll love this book. My only complaint is that the proofs of some of the statements were placed in an appendix instead of inline with the statements. Purchased 10-30-2007 at Powell's, for $28.