Editing Japanese numerals (section)

=== Decimal fractions ===

Japanese has two systems of numerals for decimal fractions. They are no longer in general use, but are still used in some instances such as batting and fielding averages of baseball players, winning percentages for sports teams, and in some idiomatic phrases such as {{Nihongo krt||五分五分の勝負|gobugobu no shōbu|'fifty-fifty chance'}}, and when representing a rate or discount. The {{tlit|ja|bu}} fractions are also used when talking about fevers—for example {{Nihongo krt||九度二分|kudonibu}} for 9 and two parts—referring to the temperature 39.2°C.

One system is as follows:

{| class="wikitable"
!align=left|Rank
|10{{sup|−1}} 
|10{{sup|−2}} 
|10{{sup|−3}} 
|10{{sup|−4}}
|10{{sup|−5}}
|10{{sup|−6}}
|10{{sup|−7}}
|10{{sup|−8}}
|10{{sup|−9}}
|10{{sup|−10}}
|- align="center"
!align="left"|Character
|{{wikt-lang|ja|分}}
|{{wikt-lang|ja|厘}}
|{{wikt-lang|ja|毛}}
|{{wikt-lang|ja|糸}}
|{{wikt-lang|ja|忽}}
|{{wikt-lang|ja|微}}
|{{wikt-lang|ja|繊}}
|{{wikt-lang|ja|沙}}
|{{wikt-lang|ja|塵}}
|{{wikt-lang|ja|埃}}
|- align="center"
!align="left"|Reading
|{{tlit|ja|bu}}
|{{tlit|ja|rin}}
|{{tlit|ja|mō}}
|{{tlit|ja|shi}}
|{{tlit|ja|kotsu}}
|{{tlit|ja|bi}}
|{{tlit|ja|sen}}
|{{tlit|ja|sha}}
|{{tlit|ja|jin}}
|{{tlit|ja|ai}}
|}

This is the system used with the traditional [[Japanese units of measurement]]. Several of the names are used "as is" to represent a fraction of a [[cun (unit)|{{tlit|ja|sun}}]].

The other system of representing these decimal fractions of rate or discount uses a system "shifted down" with a {{tlit|ja|bu}} becoming a "one hundredth" and so on, and the unit for "tenth" becoming {{tlit|ja|wari}}:
{| class="wikitable"
!align=left|Rank
|10{{sup|−1}} 
|10{{sup|−2}} 
|10{{sup|−3}} 
|10{{sup|−4}}
|10{{sup|−5}}
|- align="center"
!align="left"|Character
|{{wikt-lang|ja|割}}
|{{wikt-lang|ja|分}}
|{{wikt-lang|ja|厘}}
|{{wikt-lang|ja|毛}}
|{{wikt-lang|ja|糸}}
|- align="center"
!align="left"|Reading
|{{tlit|ja|wari}}
|{{tlit|ja|bu}}
|{{tlit|ja|rin}}
|{{tlit|ja|mō}}
|{{tlit|ja|shi}}
|}
This is often used with prices. For example:
*{{Nihongo krt||一割五分引き|ichi-wari go-bu biki}}: 15% discount
*{{Nihongo krt||打率三割八分九厘|daritsu san-wari hachi-bu kyū-rin}}: batting average .389

With the exception of {{tlit|ja|wari}}, these are rarely seen in modern usage. Decimal fractions are typically written with either kanji numerals (vertically) or Arabic numerals (horizontally), preceded by a decimal point, and are read as successive digits, as in Western convention.  Note that, in written form, they can be combined with either the traditional system of expressing numerals (42.195 kilometers: {{lang|ja|四十二・一九五 キロメートル}}), in which powers of ten are written, or with the place value system, which uses zero (50.04 percent: {{lang|ja|五〇・〇四 パーセント.}}) In both cases, however, the reading follows the traditional system ({{tlit|ja|yon-jū ni-ten ichi-kyū go kiromētoru}} for 42.195 kilometers; {{tlit|ja|go ju-tten rei-yon pāsento}} for 50.04 percent.)