Kanji involving Maths

I know this is a very weird question, but are there any Kanji involving maths? I saw the PI radical and got curious. Thanks:)

There are kanji that are related to math concepts, but most of them have other primary meanings. This is setting aside the way that you would write the normal words of reading out a math problem in spoken language.

For instance, the results of various math operations have dedicated kanji.

和 - sum (primary meaning - peace)
差 - difference (primary meaning - distinction)
積 - product (primary meaning - accumulate)
商 - quotient (primary meaning - merchandise)

But in the case of the “pi” radical, that’s just the name WaniKani gave to that part so that it’s easy to remember.

There are probably other things that don’t immediately come to mind.


If about radicals, didn’t WaniKani made up a lot of memorable names? It might not coincide with Japanese and Chinese idea of radicals, really.

It’s not related to 数学用語 at all.

I learned a few new math words today, actually. 平行 means parallel, 垂直 means perpendicular, and 水平 means horizontal, and the pronunciations are へいこう, すいちょく, and すいへい respectively. Most of these kanji are pretty early in wanikani, but I hadn’t come across these specific compounds before. Although, jisho lists the kanji for 平行 as 並行, and if I’m honest I’m not sure what the difference is. Both mean parallel, but 平行線 is parallel lines specifically, and 並行 is defined as parallel (geometry.)

Anyway, this is just a specific example, I’m no expert. If anyone can explain the へいこう thing I’d love to know!

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平行 is parallel in terms of lines not crossing
並行 is parallel in terms of moving together in the same direction or through time


Although the difference may be that 並行 can also apply to planes or other higher dimensional objects than just lines?

Ah, so maybe if you were talking about two parametric curves, you might use 並行, but if you were talking cartesian equations you might use 平行. I think I’m going to ask one of the math teachers at my school, now I’m super interested.

I’m not sure 並行 is used in math really. At least in that abstract sense. The examples I see are about physical stuff or simultaneous actions. The one thing that can throw a wrench in it is that it seems like 平行 can get used for either meaning, but 並行 doesn’t get the same cross-treatment.


Leebo coming in with the expert knowledge!

Nah… I had a general idea, but I just googled around a bit. It would still be worth asking your math teacher.

I made a list of relatively basic math terms before if you’re interested. Some of the words are made from kanji that are primarily used in a math context, but most of the kanji have non-math uses as well.


Please wait a second. I thought 足す is for numbers sum. Or does 和 means “+”?

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That’s a pretty good list, although a little tough for me because I don’t know all of the kanji yet. Since you may know, and I’ve been curious but too lazy to google it, how does Japanese differentiate between rectangle and square? Wanikani says 四角 means both…

足す is a verb, to add numbers, or to sum up numbers. 和 is a noun, it means the sum, or the result of the addition, I think


I see, you have a point here. That’s pretty unexpected that “peace” can be “sum” too. :thinking:

Yes, as I said, those kanji represent various results of operations.

Nevermind, I have googled it. Sorry to have been lazy out here in public

Pi is 円周率, the ratio between the circumference of a circle and its diameter.

We also use the greek letter π to denote that in math, but it’s also used in different contexts. For instance Π is notation for products, like Σ is for summation.

As a math student I also wanted to learn some Japanese Math Expressions in the past and found this website/pdf very usefull.