Fibonacci's Liber abaci Book

Whew. I am finished. Some very interesting algebraic problems towards the end there. I liked the geometrical solutions, but I did find that some were flawed. As such, I applied Al-Khwarizmi's method to many of them, as he did not, and I found the correct answer to some where he actually had an answer significantly different than the correct solution.

That being said, I will definitely keep this book with me. At times, I realize now how important the two major different options (Almuchabala and proportional substitution) can be because sometimes they can help solve for unknowns where the equation would have 3 or 4 different exponents (and therefore very difficult to solve without a calculator via algebra). Very important to even know about these different methods, as I had applied Algebra to some of these proportional problems and substitution and algebra both gave me different answers.

Beneath the surface of an otherwise perfunctory trading manual lies a treasure trove of philosophy behind mathematics itself. It isn't spoken on the surface, obviously (he leaves that for his Book of Squares), but the problems/equations themselves are Diophantine, and both determinate and indeterminate. Some have only one solution, some have many, some have implications that can make you just put the book down and stare into space. This is a book written by a mathematician for a mathematician. Heavy recommend.

4/5 though because it did drag on and was extremely dry.