UPDATE: I worked through these last night, and my conclusion is that the early Medievals probably had a form of arithmetic similar to the Greek love for proportions. It's possible to do these problems using algebra, but it's clunky by comparison; we wouldn't even think of problems like "if only there were twice as many, plus half of half as many, plus half of that, plus two: then we'd have a hundred!" The fact that the problems take that form implies training in recognition of ratios, and probably an easy familiarity with common ones. Proposition 4, for example, seems easy for those who are used to recognizing that this is equivalent to the ratio of 4 to 5.
2 comments:
I'm sure the fact we have coins called "quarters" is related.
See: https://en.wikipedia.org/wiki/Carolingian_monetary_system
Also, I've always found it odd how the French number in scores, but I guess it makes sense given historical roots ( https://en.wikipedia.org/wiki/Vigesimal ), and how doing math in your head is easier for a lot of people if it's rooted in proportions rather than just numbers.
Also, TIL that Inches were once "ounces of a foot".
Post a Comment