Grant, This is a very good "mathematical biography" of Leonardo Pisano ("Fibonacci"), focusing not only on the practical applications of the Hindu-Arabic numerals that he helped to popularize, but also on the many other contributions he made. One thing you didn't mention, but that is decidedly odd, is that he is mostly known today by a name that he would not have recognized (he never used it himself), and that he is best remembered for what amounts only to a very small part of what he did. This is not all that rare, though. What is remembered of a mathematician's work is mostly determined by what other people are able to understand and make use of. One comment about what you say about the adoption of the Hindu-Arabic numerals: Although people could get very fast with arithmetic on an abacus, a real defect for uses in business was that once the calculation was finished, there was no record apart from the final answer. That meant there was really no way to check a result except to repeat the whole calculation! With arithmetic done with written numerals on paper, you do have a complete record and you can check the results by verifying the steps! The main comment I have is that I am really glad that looked for more information about his book called the "Liber Quadratorum" (Book of Squares) in addition to other the works that you discuss. There, we can see some direct influence from the Diophantos-style theory of solving numerical equations. This work also became the source of later results in number theory by some very influential 18th and 19th century mathematicians. When you discuss the Fibonacci sequence 1,1,2,3,5,8,11, ... I think "most renowned" is probably an overstatement. It's certainly the best-known mathematical idea with his name attached to it, but I think most people recognize the Fibonacci sequence is interesting more for its own properties than for the fact that Fibonacci introduced it. Grade: A