This question might have to do with more etymology and grammar than it has to do with the language itself, but I wanted to know.
Do the Japanese use the number system of ten because they have ten fingers to count with? Or did it spread to Japan that everyone – after the golden age of mathematics – had used numbers of ten-units.
Because we know it’s possible to use different units. The Greeks used units of 60 (which is why time is in units of 60).
I’m curious. Was this something that naturally developed in the Japanese language or was the mathematical revolution simply so influential that an island nation that had little contact with any country except for China still HAD to adopt the system.
And could you point to your sources? Thank you.
4 comments
Seems to be unknown, but this led me down a rabbit hole filled with fascinating things. Hope everyone will enjoy.
https://en.m.wikipedia.org/wiki/Japanese_mathematics
https://www.ndl.go.jp/math/e/s2/3.html
https://www.asahi.com/sp/ajw/articles/14437190
Dunno when the western world started using a number system that goes to ten. But the old system Japan used before metric originated in china, as far as I know, and was from one-ten. Japanese carpenters still use it today. Shaku and sun
I found [this article](https://mainichi.jp/articles/20210901/k00/00m/040/348000c) linked from the Japanese Wiki article on the [decimal system](https://ja.wikipedia.org/wiki/%E5%8D%81%E9%80%B2%E6%B3%95#cite_ref-4).
Seems it’s been in use in Japan since at least the Yayoi period, based on finding a pair of stones used as standard weights (the larger one is 10 times heavier than the smaller one). Those were dated to ~1c or 2c BCE. The Yayoi period was marked by movement of people to Japan from the Korean peninsula, so [my speculation] they could have brought decimals with them (which existed in China since at least 14c BCE) or learned them from the people who were already there, but there currently doesn’t seem to be any more evidence to say.
> everyone had used 10 units
Not everyone. I lived in Cambodia for a bit last year and they use a base 5 counting system. One can only presume due to the same reason others chose a base 10 system.