Jack, 

      This is a very good "mathematical biography" of 
    Leonardo Pisano ("Fibonacci"), focusing on the practical
    applications of the Hindu-Arabic numerals that he helped
    to popularize.  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 older practice
    of computing with an abacus:  Although people could get
    very fast and adept with those operations, a real defect
    for 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
    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 think it would
    have been interesting to look for more information about
    his book called the "Liber Quadratorum" (Book of Squares)
    in addition to 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.

    Grade:  A-