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Subject: Re: Japanese grammar & reading math symbols
From: TAKASUGI Shinji (tssf.airnet.ne.jp)
Date: Tue, 11 Mar 2003 16:39:12 GMT
References: 1


> 3 足す 5 は 8。
> san tasu go wa hachi.
>
> My question is, is this way of expressing mathematical relations a fairly new phenomenon -- after Japan's contact with the West (which, I assume, invented the notation)?

Right. As far as I know, Japanese mathematicians used the following expressions before Westernization:
(じゅう) () 相併 (あいあわ) せて 十五を () る。 (10 + 5 = 15)
十と 五を 内減 (ないげん) して 五を 得る。 (10 - 5 = 5)
十を 五を (もっ) (げん) じて 五を 得る。 (10 - 5 = 5)
十と 五を 相乗 (あいじょう) じて 五十を 得る。 (10 × 5 = 50)
十を 五を以て (じょ) して () を 得る。 (10 / 5 = 2)

They used 十干 for known numbers like a, b, and c in modern math, and used 十二支 for unknown numbers like x, y, and z. They also used digits based on 算木 (さんぎ), counting rods (算籌 in Chinese).

ex.
≡||甲 (32a)
=|○|甲乙 (2101ab)
−|||甲|乙 (13a/b)
||子三 (2x4)

> I'm thinking that 3 足す 5 は 8 has a verb serving as operator in between the numbers. Is this a "natural" word sequence for Japanese?

The operators 足す, 引く, かける, and 割る work as coordinating conjunctions like と rather than verbs.



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