Japanese numerals

There are two ways of writing the numbers in Japanese: in Arabic numerals (1, 2, 3) or in Chinese numerals (一, 二, 三). 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 (On reading) and a native Japanese reading (Kun reading) used somewhat less formally for numbers up to 10. In some cases (listed below) the Japanese reading is generally preferred for all uses. Archaic readings are marked with †.

* The special reading 〇 maru (which means "round" or "circle") 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 ichi-maru-kyū (Kanji: 一〇九). (It can also be read as 'ten-nine'—pronounced tō-kyū—which is a pun on the name of the Tokyu department store which owns the building.) This usage of maru for numerical 0 is similar to reading numeral 0 in English as oh. However, as a number, it is only written as 0 or rei (零). Additionally, two and five are pronounced with a long vowel in phone numbers (i.e. にい nī and ごお gō).

As noted above, yon (4) and nana (7) are preferred to shi and shichi. It is purported that this is because shi is also the reading of the word death (死), which makes it an unlucky reading (see tetraphobia); while shichi may sound too similar to ichi (1), shi or hachi (8). However, in quite a number of established words and phrases, shi and shichi are preferred; additionally, when counting (as in "ichi, ni, san, shi,..."), shi and shichi may be preferred.

The number 9 is also considered unlucky; when pronounced ku, it is a homophone for suffering (苦). 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.[2]

In modern Japanese, cardinal numbers except 4 and 7 are generally given the on readings. Alternate readings are used in month names, day-of-month names, and fixed phrases; for instance, April, July, and September are called shi-gatsu (4th month), shichi-gatsu (7th month), and ku-gatsu (9th month) respectively (for further detail see Japanese counter word#Exceptions). The on readings are also used when shouting out headcounts (e.g. ichi-ni-san-shi).

Larger numbers are made by combining these elements:

• Tens from 20 to 90 are "(digit)-jū" as in 二十 (ni-jū) to 九十 (kyū-jū).
• Hundreds from 200 to 900 are "(digit)-hyaku".
• Thousands from 2000 to 9000 are "(digit)-sen".

Starting at 万 (10,000), numbers begin with 一 (ichi) if no digit would otherwise precede. That is, 100 is just 百 hyaku, and 1000 is just 千 sen, but 10,000 is 一万 ichiman, not just *man. (This differs from Chinese, where numbers begin with 一 if no digit would otherwise precede starting at 100.) And, if 千 sen directly precedes the name of powers of myriad, 一 ichi is normally attached before 千 sen, which yields 一千 issen. That is, 10,000,000 is normally read as 一千万 issenman. But if 千 sen does not directly precede the name of powers of myriad or if numbers are lower than 2,000, attaching 一 ichi is optional. That is, 15,000,000 is read as 千五百万 sengohyakuman or 一千五百万 issengohyakuman, and 1,500 as 千五百 sengohyaku or 一千五百 issengohyaku.

There are some phonetic modifications to larger numbers involving voicing or gemination of certain consonants, as typically occurs in Japanese (i.e. rendaku): e.g. roku "six" and hyaku "hundred" yield roppyaku "six hundred".

* This also applies to multiples of 10. Change ending -jū to -jutchō or -jukkei.
** This also applies to multiples of 100. Change ending -ku to -kkei.

In large numbers, elements are combined from largest to smallest, and zeros are implied.

Getabako

As with Chinese numerals, there exists in Japanese a separate set of kanji for numerals called daiji (大字) 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 (the numbers 4 to 9 as well as 100, 1000 and 10000 are written identically to the common ones, cf. table below).[3] These numbers' common forms can be changed to a higher value by adding strokes (1 and 2 were explained above, while 3 can be changed to 5, and 10 to 1000). 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 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 Jōdai Tokushu Kanazukai for information on subscript notation.

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 (folding down) the fingers, starting from the thumb – thus one has just the thumb down (and others extended), 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 (indicating five) and places the appropriate number of fingers from the other hand against the palm (palms facing each other) – so six has the index finger against the palm, and so forth.[4] To display ten, one presents both hands open and palm outwards.

Since the adoption of Arabic numerals, numbers have become written in Arabic numerals more and more often. Counters and ordinal numbers are typically written in Arabic numbers, such as 3人 (san-nin, three people), 7月 (shichigatsu, July, "seventh-month"), 20歳 (hatachi, age 20), etc., although 三人, 七月 and 二十歳 are also acceptable to write (albeit less common). However, numbers that are part of lexemes are typically written in kanji. For example, the term yaoya (八百屋, 'vegetable stand / grocer') translates into "800 store", uses the Old Japanese pronunciation for 800, ya(h)o. The notorious Japanese organized crime syndicate, the yakuza, can be written 八九三 (or 893), a hand in oicho-kabu that is worth 0 points, indicating that yakuza are "worthless persons" or "gambling persons".[5]

• Chinese numerals
• Decimal mark
• Japanese counter word
• Japanese people
• Japanese wordplay § Numeric substitution

• 大数の名前について (in Japanese)
• Ancient Japanese number system Archived 2018-08-29 at the Wayback Machine
• English exercises for learning Japanese numerals
• Audio to learn the pronunciation for Japanese numbers
• Convert kanji numerals to arabic numerals (sci.lang.Japan FAQ page)
• Convert arabic numerals to kanji numerals (sci.lang.Japan FAQ page)