All the ways of writing numbers


I couldn't find any sites where I could get a comprehensive list of possible
number writing formats. My question is mainly about mixing and matching
different ideas I've seen online.

For general, whole numbers, which of these are possible:

一二三万三四五

１２３万３４５

百2十3万３百４十５

１２３３４５

一二三三四五

For rationals, the only real question I have is if you can mix decimal
fractions with whole numbers like so: 百二点一厘 for 102.01, or if you need to do
it like 百二点〇一 or anything similar.




You can get a good overview from the government's official guideline
[公用文作成の考え方](https://www.bunka.go.jp/seisaku/bunkashingikai/kokugo/hokoku/pdf/93651301_01.pdf)
(see Annex I-4), which was just revised this year, though it is not the only
decisive rules.

In general, there are several modes of consistent styles for horizontal and
vertical writings respectively, and mixing conventions from multiple systems
is not a recommended practice.

  1. For horizontal writing

    1. Positional notation, Western-style separators

> 123,045,067.089

    2. Positional notation, Japanese separators

> 1億2304万5067.089

Note 1: Japanese fractional units (割, 分, 厘……) are **not** to be used together
with most of dimensionless units larger than 1.

Note 2: there sometimes seen thousand-based delimiting in statistic or
financial fields to align with Western ledger sheets.

> 123百万045千067.089

    3. Spelled out

> 一億二千三百四万五千六十七点〇八九 or  
>  一億二千三百四万五千六十七・〇八九

    4. (bonus) Anti-forgery spelling for accounting ([大字](https://ja.wikipedia.org/wiki/%E5%A4%A7%E5%AD%97_\(%E6%95%B0%E5%AD%97\)))

> 壱億弐阡参陌肆萬伍阡陸拾漆円  
>  壱億弐千参百四万五千六拾七円 (legal style)  
>  etc.

  2. For vertical writing

    1. Positional notation, Western-style separators

> 一二三、〇四五、〇六七・〇八九

However, for numbers in fixed formats and/or of small amount (e.g. dates, ID,
percentage...), Arabic numerals are also used. Such lesser digit numbers are
often packed into one character size in professional typesetting
([縦中横](https://www.w3.org/TR/jlreq/#handling_of_tatechuyoko)). See:
[![公用文作成の考え方 解説
p.16](https://i.stack.imgur.com/g52iB.png)](https://i.stack.imgur.com/g52iB.png)

    2. Positional notation, Japanese separators

> 一億二三〇四万五〇六七・〇八九

    3. Spelled out  
(same as 1-3)

    4. Anti-forgery spelling  
(same as 1-4)

The fullwidth vs. halfwidth Arabic numeral usage is a highly controversial
topic with much disagreement across house rules, but unless you are a
typesetter, sticking to halfwidth figures seems the best practice.




You can get a good overview from the government's official guideline
[公用文作成の考え方](https://www.bunka.go.jp/seisaku/bunkashingikai/kokugo/hokoku/pdf/93651301_01.pdf)
(see Annex I-4), which was just revised this year, though it is not the only
decisive rules.

In general, there are several modes of consistent styles for horizontal and
vertical writings respectively, and mixing conventions from multiple systems
is not a recommended practice.

  1. For horizontal writing

    1. Positional notation, Western-style separators

> 123,045,067.089

    2. Positional notation, Japanese separators

> 1億2304万5067.089

Note 1: Japanese fractional units (割, 分, 厘……) are **not** to be used together
with most of dimensionless units larger than 1.

Note 2: there sometimes seen thousand-based delimiting in statistic or
financial fields to align with Western ledger sheets.

> 123百万045千067.089

    3. Spelled out

> 一億二千三百四万五千六十七点〇八九 or  
>  一億二千三百四万五千六十七・〇八九

    4. (bonus) Anti-forgery spelling for accounting ([大字](https://ja.wikipedia.org/wiki/%E5%A4%A7%E5%AD%97_\(%E6%95%B0%E5%AD%97\)))

> 壱億弐阡参陌肆萬伍阡陸拾漆円  
>  壱億弐千参百四万五千六拾七円 (legal style)  
>  etc.

  2. For vertical writing

    1. Positional notation, Western-style separators

> 一二三、〇四五、〇六七・〇八九

However, for numbers in fixed formats and/or of small amount (e.g. dates, ID,
percentage...), Arabic numerals are also used. Such lesser digit numbers are
often packed into one character size in professional typesetting
([縦中横](https://www.w3.org/TR/jlreq/#handling_of_tatechuyoko)). See:
[![公用文作成の考え方 解説
p.16](https://i.stack.imgur.com/g52iB.png)](https://i.stack.imgur.com/g52iB.png)

    2. Positional notation, Japanese separators

> 一億二三〇四万五〇六七・〇八九

    3. Spelled out  
(same as 1-3)

    4. Anti-forgery spelling  
(same as 1-4)

The fullwidth vs. halfwidth Arabic numeral usage is a highly controversial
topic with much disagreement across house rules, but unless you are a
typesetter, sticking to halfwidth figures seems the best practice.

