This novel is a biography of Fra Luca Pacioli in fictionalized form. Pacioli who lived from 1447 to 1517 was an Italian mathematician and Franciscan friar who authored one of the first printed mathematics textbooks, collaborated with famous artists (especially Leonardo da Vinci, who illustrated his book Divina Proportione), was wellconnected at the Vatican, and helped to create the methods of modern bookkeeping.
Within the framework of Pacioli reciting his life to a young monk as he lays dying, this is basically a factual telling of the life of a historical figure with a few embellishments.
The reader gets to watch the protagonist grow and learn, and can vicariously enjoy meeting popes and the most famous Renaissance artists. But, honestly, Pacioli's life is not terribly exciting. Still, it is written well enough to be quite readable and there is inspiration to be found in the pages. Because it is published in the "Mentoris Project" series of books, it especially focuses on the people who mentored Pacioli, within the art world and within the hierarchy of the Church, as well as within mathematics.
Some mathematical notes:
 There are some anachronisms. In the book Pacioli says:
(quoted from The Divine Proportions of Luca Pacioli)
Now, only a decade after printing precise figures was made possible, my Summa was going to be the first printed book do deal with HinduArabic arithmetic.

This may be historically accurate, but I don't think he would have been aware of the notation's Hindu origins and would only have called it "Arabic". Also, at one point he mentions "linear algebra". I don't think there was any such thing at that point in history.
 There is quite a lot about mathematics education in this book. It arises first as he is learning mathematics himself, continues through his first job as a private tutor for three children, and culminates with him as a famous textbook author and one of the first professors of mathematics at a European university.
 Pacioli expresses his love for Fibonacci's book "Liber Abaci" and insists that the young scribe recording his life story label the chapters of the book with the numbers from the Fibonacci sequence. Just before dying, Pacioli hints to the scribe that there is a secret relevance to the use of those numbers in his life story. It is left for the reader to figure out that he was going to explain how they are connected to the "Divine Proportion" (i.e. the Golden Mean) which was the subject of one of his books and referenced in the title of this one.
 I don't know if there is historical evidence to support this, but a very interesting part of the book was his debates with Leonardo da Vinci about the significance of "the divine proportion" and the fact that it shows up in nature. Being a devout Catholic, Pacioli sees it as evidence of God, while da Vinci is portrayed as being an atheist who believes that it arises for logical (not supernatural) reasons.
Thanks to Allan Goldberg for mentioning this book to me. It certainly belongs in my database of mathematical fiction and is recommended to anyone who would enjoy a realistic account of the role that mentors played in the life of a historical figure who influenced the teaching and practice of mathematics. 