Japanese numerals

The Japanese numerals are numerals that are used in Japanese. In writing, they are the same as the Chinese numerals, and large numbers follow the Chinese style of grouping by 10,000. Two pronunciations are used: the Sino-Japanese readings of the Chinese characters and the Japanese .

Basic numbering in Japanese

There are two ways of writing the numbers in Japanese: in Arabic numerals or in Chinese numerals. The Arabic numerals are more often used in horizontal writing, and the Chinese numerals are more common in vertical writing.
Most numbers have two readings, one derived from Chinese used for cardinal numbers and a native Japanese reading used somewhat less formally for numbers up to 10. In some cases the Japanese reading is generally preferred for all uses. Archaic readings are marked with †.

Number	Character	reading	reading	Preferred reading
0	/
1
2
3
4			,
5
6
7
8
9		,
10
20			†
30			†
40			†
50			†
60			†
70			†
80			†
90			†
100			†
500			†
800			†
1,000			†
10,000			†
100,000,000			—
1,000,000,000,000			—
10,000,000,000,000,000			—

* The special reading is also found. It may be optionally used when reading individual digits of a number one after another, instead of as a full number. A popular example is the famous 109 store in Shibuya, Tokyo which is read as . This usage of for numerical 0 is similar to reading numeral 0 in English as oh. However, as a number, it is only written as 0 or. Additionally, two and five are pronounced with a long vowel in phone numbers.
As noted above, and are preferred to and. It is purported that this is because is also the reading of the word, which makes it an unlucky reading ; while may sound too similar to, or . However, in quite a number of established words and phrases, and are preferred; additionally, when counting, and may be preferred.
The number 9 is also considered unlucky; when pronounced, it is a homophone for. The number 13 is sometimes considered unlucky, though this is a carryover from Western tradition. In contrast, 7 and sometimes 8 are considered lucky in Japanese.
In modern Japanese, cardinal numbers except 4 and 7 are generally given the readings. Alternate readings are used in month names, day-of-month names, and fixed phrases; for instance, April, July, and September are called,, and respectively. The readings are also used when shouting out headcounts.
Larger numbers are made by combining these elements:

Tens from 20 to 90 are "" as in to.
Hundreds from 200 to 900 are "".
Thousands from 2000 to 9000 are "".

Starting at a myriad, numbers begin with if no digit would otherwise precede. That is, 100 is just, and 1000 is just, but 10000 is, not just *. And, if directly precedes the name of powers of myriad, is normally attached before, which yields. That is, 10,000,000 is normally read as. But if does not directly precede the name of powers of myriad, attaching is optional. That is, 15,000,000 is read as or, just as 1500 is read as or.
There are some phonetic modifications to larger numbers involving voicing or gemination of certain consonants, as typically occurs in Japanese : e.g. "six" and "hundred" yield "six hundred".

×	1	2	3	4	5	6	7	8	9	10	100	1000
100										—	—	—
1,000										—	—	—
10										*
10										*	**

* This also applies to multiples of 10. Change ending to or.

** This also applies to multiples of 100. Change ending to.
In numbers above 10, elements are combined from largest to smallest, and zeros are implied. Japanese numerals are multiplicative additive rather than positional; to write the number 20 you get the character for two and then the character for ten to get two tens or twenty.

Number	Character	Reading	Basic Meaning
11	十一		Ten and One
17	十七		Ten and Seven
151	百五十一		Hundred, Five Tens and One
302	三百二		Three Hundreds and Two
469	四百六十九		Four Hundreds, Six Tens and Nine
2025	二千二十五		Two Thousands, Two Tens and Five

Strings of digits and decimal numbers

The above digits from 1 to 9 are used primarily in isolation. Strings of digits make use of slightly different readings, with lengthened vowels, for 2 and 5, and less frequently, 4 and 9. This is because when digits are enumerated, if possible, they must be so in groups of two, each of which must consist of exactly four morae, which necessitates the lengthening of normally unimoraic digits such as ni, go, shi and ku. For example, such string as 54'262 is pronounced gō-yon nī-roku ni, with the first two groups being quadrimoraic. The accent is placed on the penultimate mora of each group if possible, hence.
This rule also applies to the last digit of the integer part and all the digits of the decimal part of a decimal number. For example, such decimal number as 252'.255 is pronounced nihyaku gojū nī-ten nī-gō go, with ten meaning "point".

Other types of numerals

For ordinal numbers, see Japanese counter word#Ordinal numbers.
Distributive numbers are formed regularly from a cardinal number, a counter word, and the suffix, as in.

Powers of 10

Large numbers

Following Chinese tradition, large numbers are created by grouping digits into myriads rather than the Western thousands :

Rank	10	10	10	10	10	10	10	10	10	10	10	10	10	10	10	10	10
Character						,									,
Reading						,

Variation is due to the, Japan's oldest mathematics text. The initial edition was published in 1627 and had many errors, most of which were fixed in the 1631 edition. In 1634, there was yet another edition which again changed a few values. The above variation is due to inconsistencies in the latter two editions. There are different characters for 10, and after 10 they differ in whether they continue increasing by a factor of 10 or switch to 10.
The first three numbers with multisyllabic names and variation in assigned values ultimately derive from India, though they did not have defined values there. was originally used in Buddhist scripture for an indefinitely large quantity; it derives from the Sanskrit गङ्गा 'Ganges' and, referring to the innumerable sands of the Ganges River., from Sanskrit असंख्येय 'uncountable/innumerable', with the negative prefix, and is from Sanskrit नयुत/नयुतः. After that, the numbers are Buddhist terms translated into or coined in Chinese and later assigned numerical values: and.
Examples:

1 0000 :
983 6703 :
20 3652 1801 :

However, numbers written in Arabic numerals are separated by commas every three digits following English-speaking convention. If Arabic numbers and kanji are used in combination, Western orders of magnitude may be used for numbers smaller than 10,000.
In Japanese, when long numbers are written out in kanji, zeros are omitted for all powers of ten. Hence 4002 is 四千二 : e.g. or instead of the normal.

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, and when representing a rate or discount. The fractions are also used when talking about fevers—for example for 9 and two parts—referring to the temperature 39.2°C.
One system is as follows:

Rank	10	10	10	10	10	10	10	10	10	10
Character
Reading

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

Rank	10	10	10	10	10
Character
Reading

This is often used with prices. For example:

: 15% discount
: batting average.389

With the exception of, these are rarely seen in modern usage. Decimal fractions are typically written with either kanji numerals or Arabic numerals, 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, in which powers of ten are written, or with the place value system, which uses zero In both cases, however, the reading follows the traditional system

Formal numbers

As with Chinese numerals, there exists in Japanese a separate set of kanji for numerals called used in legal and financial documents to prevent unscrupulous individuals from adding a stroke or two, turning a one into a two or a three. The formal numbers are identical to the Chinese formal numbers except for minor stroke variations. Today, the numbers for one, two, three, and ten are written only in their formal form in legal documents. These numbers' common forms can be changed to a higher value by adding strokes. In some cases, the digit 1 is explicitly written like 壱百壱拾 for 110, as opposed to 百十 in common writing.
Formal numbers:
The four current banknotes of the Japanese yen, 1000-yen, 2000-yen, 5000-yen, and 10000-yen, have formal numbers 千, 弐千, 五千, and 壱万, respectively.

Old Japanese

Old Japanese shares some vocabulary with later periods, but there are also unique number terms over 10 which are not used any more, aside from being parts of specific lexemes.
Notes:

The transcription is based on the phoneme and is not phonetic. See Old Japanese for further information.
See for information on subscript notation.

Number	Reading	Examples	Notes
1	[wiktionary:一#Noun 2\|]	一日, 一年
2	[wiktionary:二#Noun 2\|]	二夜
3	[wiktionary:三#Noun 2\|]	三十
4	[wiktionary:四#Noun 2\|]	四十, 四人
5	[wiktionary:五#Noun 2\|]	五年
6	[wiktionary:六#Noun 2\|]	六爪
7	[wiktionary:七#Noun\|]	七瀬	Often used to mean many.
8	[wiktionary:八#Noun 2\|]	八雲	Often used to mean many.
9	[wiktionary:九#Noun 2\|]	九柱
10	[wiktionary:十#Noun 2\|] / [wiktionary:十#Noun 3\|]	十日
10	[wiktionary:十#Noun\|]	三十, 四十, 六十, 八十	Found only in compound words; not used alone.
20	[wiktionary:二十#Noun\|]	二十, 二十人, 二十年
50	[wiktionary:五十\|]	五十日
100	[wiktionary:百#Noun 2\|]	五百, 五百年, 五百夜, 八百, 三百, 六百, 九百	Used for multiple hundreds in compound numerals. Often used to mean many.
100	[wiktionary:百#Noun 3\|]	百日	Used for non-multiple hundred and for the number "100" by itself. Often used to mean many.
1000	[wiktionary:千#Noun\|]	千年	Often used to mean many.
10000	[wiktionary:万#Noun\|]	八百万	Often used to mean many.

Hand counting

Japanese uses separate systems for counting for oneself and for displaying numbers to others, which both proceed up to ten. For counting, one begins with the palm open, then counts up to five by curling up the fingers, starting from the thumb – thus one has just the thumb down, while four has only the little finger extended, and five has a fist. One then counts up to ten by proceeding in the reverse order, extending the fingers, starting at the little finger – thus six is the same as four, seven the same as three, and so forth, with ten ending with the palm open. While this introduces ambiguity, it is not used to present to others, so this is generally not a problem. When displaying for others, one starts with the hand closed, and extends fingers, starting with the index, going to the little finger, then ending with the thumb, as in the United States. For numbers above five, one uses an open hand and places the appropriate number of fingers from the other hand against the palm – so six has the index finger against the palm, and so forth. To display ten, one presents both hands open and palm outwards.

Digits in written words

Since the adoption of Arabic numerals, it has become more and more common for numbers to be written using them. Counters and ordinal numbers are typically written in Arabic numbers, such as,,, etc., although 三人, 七月 and 二十歳 are also acceptable to write. However, numbers that are part of lexemes are typically written in kanji. For example, the term translates into "800 store" and uses the Old Japanese pronunciation for 800,. The notorious Japanese organized crime syndicate, the yakuza, can be written 八九三, a hand in that is worth 0 points, indicating that yakuza are "worthless persons" or "gambling persons".