# Prefixing `一` to numbers

It seems to me that `千` is exceptional in having it prefixed with `一`.

• As for `一`, `十`, `百`, they work together with `千` to describe the numbers from 1 to 9999, so they compete with one another, or are complimentary. There is no combination like:

一一, 一十, 一百, 十十, 十百 百百

• As for `万`, `億`, `兆`, `京`, etc., they are multiplied by a number from 1 to 9999, expressed by the prefix using `一` `十`, `百` `千`, so when that prefix turns out to be 1, 10, 100, 1000, then they are combined, and there are combinations like:

一万, 十万, 百万, 千万, 一億,　十億, 百億, 千億, etc.

• and there is no combination among themselves such as

万万, 万億, 億億, 万兆, 億兆, 兆兆, etc.

However, `千` is exceptional in that it is prefixed by `一` just when itself is prefixed to the characters `万`, `億`, `兆`, `京`, etc.

Why is `千` prefixed with `一` in this case? Why is it not like the following?

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I do not know if the “why” questions like this is answerable at all. Probably some people can come up with a few guesses, but I am not sure if there is a way to verify or disprove those claims. – Tsuyoshi Ito Dec 28 '11 at 2:26
Maybe one can lookup the historical usage in Classical Chinese? – syockit Feb 2 '12 at 6:18

## 2 Answers

I'm mostly guessing here, but I think it might be in order not to mistake them for 三万 and 三億 when spoken. While せんまん and さんまん only differ by a vowel, いっせんまん and さんまん are easy to distinguish.

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Why does it get confusing with 三万 and 三億 without 一 ? – user458 Feb 7 '12 at 15:34
Sorry, not sure I understand the question. せんまん and さんまん only differ by a vowel. いっせんまん and さんまん are easy to distinguish. – dainichi Feb 7 '12 at 15:42
I see. I didn't realize that you were mentioning the pronunciation. That seems reasonable. It's actually very convicing. Thanks. – user458 Feb 7 '12 at 15:48

I think the answer to this question has more to do with mathematics than language. The point of having repeated values is to make counting easier. If every new order of number had its own name, it would be "very" difficult to remember them all or tell them at a glance. Also, if we didn't have new names for each "grouped order" (not really sure what these are called), then there would be numerous (no pun intended) ways to name one value.

What I mean is, you ask why there is (for example) no `万万`. The same reason there is no 1,000-1,000 in English: because the order "million" has been established. If there was no concept of millions, then the value 1000000 could be described any number of (numerous, if not infinite) ways: 10-100000, 100-10000, 1000-1000, 10000-100, 100000-10, 500-2000, 40-25000, ...; and there would be no consistency amongst what different people use. Since everyone knows the concepts of millions, it's easy to instantly see and understand the magnitude of such a value.

Why is 千 prefixed with 一 in this case? Why is it not like the following?

That's the only way I've heard those numbers. I've never heard `一千`,`一千万` or `一千億` outside of "formal" documents, etc.

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Sorry, but I don't think you understand my question, and you do not give an answer to it. – user458 Feb 7 '12 at 17:14