Japanese numerals: Encyclopedia II - Japanese numerals - Powers of 10

Japanese numerals - Powers of 10

Japanese numerals - Large numbers

Following Chinese tradition, large numbers are created by grouping digits in myriads (every 10,000) rather than the Western thousands (1000):

Examples: (spacing by groups of four digits is given only for clarity of explanation)
1`0000 : 一万 : ichi-man
983`6703 : 九百八十三万六千七百三 : kyū-hyaku hachi-jū san man, roku-sen nana-hyaku san
20`3652`1801 : 二十億三千六百五十二万千八百一 : ni-jū oku, san-zen rop-pyaku go-jū ni-man, sen hap-pyaku ichi

However, numbers written in Arabic numerals are separated by commas every three digits following Western convention.

In Japanese, when long numbers are written out in kanji, zeros are omitted for all powers of ten. Hence 302 is 三百二. In contrast, Chinese requires the use of 零 wherever a zero appears, e.g. 三百零二 for 302.

Japanese numerals - 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 五分五分の勝負 "fifty-fifty chance"), and when representing a rate or discount.

One system is as follows:

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 shaku.

The other system of representing these decimal fractions of rate or discount uses a system "shifted down" with a bu becoming a "one hundredth" and so on, and the unit for "tenth" becoming wari:

This is often used with prices. For example:
一割五分引き ichi-wari go-bu biki "15% discount"
打率三割八分九厘 daritsu san-wari hachi-bu kyū-rin "batting average .389"

With the exception of 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 they can be combined with either the traditional system of expressing numerals (42.195 kilometers: 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: 五〇・〇四 パーセント).

Adapted from the Wikipedia article "Powers of 10", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki