Yes, I know, I NEVER talk about math!
Don’t look at me, it was Iva Sallay at Find the Factors‘ suggestion! (https://findthefactors.com/).
An invite, actually, to write a math-themed blog that Iva Sallay could possibly include in her “Playful Math Education Blog Carnival” that Sallay is hosting!
And one that I was thrilled to even be considered for!
I’ve followed Iva Sallay for so long I can’t even remember how we “met” but I kept following “Find the Factors” because I wanted to see if I could improve my math skills, and, at least, reach the level of the brilliant-at-math third graders I sometimes taught.
(I get numbers switched around a lot, like dyslexia but with numbers, and I even have trouble telling time. Ironically, even though teachers and others mocked me when I was growing up, I actually had a job once as a closing manager for a grocery store, and had to count out the tills at night and make the financial reports. And I actually became pretty good at it!)
A later workplace skills assessment even showed me that my math skills were actually within the average range.
Nothing to write home about, but nowhere near as pitiful as I once thought they were (I probably could have gone to school for Marine Biology after all, with some academic support and tutoring for math!).
Speaking of “writing home”, Iva Sallay offered the aforementioned invite to join in the Math Carnival fun after I posted up about the book set I am currently reading.
This book set (three books) showcases a fifteenth-century maritime manuscript by a Venetian mariner named Michael of Rhodes.
I purchased the set at a history conference in Florida, because I loved maritime history (I have an MA in history).
But the main portion of this fifteenth-century manuscript that Michael of Rhodes wrote (and/or recorded, as some of the scholars discuss in their essays in the third volume) is math! And I am so, so intimidated by math.
The book set contains three books: a facsimile of the original manuscript (which includes original drawings, charts, and equations), a typed version of the manuscript, and adjoining pages where the text of Michael of Rhodes folios is provided in an English translation.
Included in the last book is a chapter study written by Raffaella Franci (https://openlibrary.org/authors/OL1328338A/Raffaella_Franci) titled “Mathematics in the Manuscript of Michael of Rhodes”, where Franci dissects the math, and Michael of Rhodes’ motivation in including, of the equations that take up “about half” (Franci 2009, 115) of the manuscript.*
Franci concludes that Michael of Rhodes wrote this manuscript as a fifteenth-century version of a CV, or resume (Franci 2009, 146). After he finished his “service at sea” (Franci 2009, 146), he was hoping obtain a “post in public administration” (Franci 2009, 146).
Raffaela Franci also surmises in the mathematics chapter study that much of the math Michael of Rhodes included in his manuscript went above and beyond what was required as part of his profession (Franci 2009, 146). Franci hypothesizes that Michael’s extensive inclusion of mathematics in his manuscript to one key reason–Michael of Rhodes simply “fell in love with the subject” (Franci 2009, 146).
Even as a self-identified “non-math” person, I’m fascinated. I mean, come on, fifteenth-century math problems that this Venetian mariner did for fun? How cool is that?
Michael of Rhodes starts out with something called “practical arithmetic, or abbacus mathematics” (Franci 2009, 115). And, in addition to algebra, the rule of three, fractions, square roots, cube roots, and more (Franci 2009, 117-118), Michael of Rhodes treats math lovers with maritime/trade “problems”: “Commerce of pepper…freightage…buying jewels…travels…” (Franci 2009, 117-118) and even problems about “playing dice” (Franci, 118).
According to Rafaella Franci, Michael of Rhodes used something called the “Divisione a Galera”–the “Galley Method of Division” for his many calculations (Franci 2009, 119) and Franci provides the reader with a more detailed examination of this method (and other approaches to solving problems) within the chapter study of this manuscript.
Raffaela Franci states that Michael’s personal fascination with mathematics led him to calculate solutions purely as a theoretical exercise, because his solutions are so “complicated” that they “have no practical use” (Franci 2009, 143).
On the lighter side, but just as historically fascinating, is Michael of Rhodes’ examination of astrology and horoscopes in relation to not only successful maritime navigation, but in navigating the murky waters of business deals, health and wellness, one’s own personality assessment, and even in interpersonal relationships.
Some things never change, right?
And, if we embrace Raffaela Franci’s conclusion, Michael of Rhodes created this whole document for what many of us strive for today–a better job!
Source as quoted/used as reference for this blog post:
Fauci, Raffaella. 2009. “Mathematics in the Manuscript of Michael of Rhodes.” Pp. 115-146 in The Book of Michael of Rhodes: A Fifteenth-Century Maritime Manuscript, Volume 3: Studies, edited by Pamela O. Long. Cambridge, MA: Massachusetts Institute of Technology.
Links for the book set: