Fundamental Concepts of Mathematics
I rarely talk about the books I buy, usually a few each month but one is worth mentioning. Last night I bought a book on Mathematics called Foundations and Fundamental Concepts of Mathematics, by Howard Eves, who was once quoted as saying "A formal manipulator in mathematics often experiences the discomforting feeling that his pencil surpasses him in intelligence".
This quote above certainly applies to me as I often feel well.. stupid when it comes to mathematics. It's hard for me to grasp concepts if they have no context of use. For instance, if you were to tell me about what's involved in Kalman filtering my eyes would glaze over and I'd probably start daydreaming about being the next real black sheep rapper. But if you showed me a Kalman filter and then showed how it applied to control theory, then used aircraft navigation as an example I would pick it up much quicker. Throw in some history of how it came about and it's locked in.
Well this book is a perfect example of how a mathematics book should be written. It will not only give you an idea of modern math concepts but also show you the history of these concepts and how they came about. From Euclid's Elements to complex numbers this book covers a ton of good information for those wanting to expand their math knowledge or maybe just those that like history. For about $15 USD you can't beat it.