If you've learned 100 Japanese words (or especially 100 kanji), those probably include thirteen numbers: 一 二 三 四 五 六 七 八 九 十 (1 through 10), 百 (100), 千 (1,000) and 万 (10,000). With these you can handle most of the integers you might run into.
To complicate your study, there is another set of readings to learn: ひとつ, ふたつ, みっつ and so on. Oh well. Just as most kanji have 音読み (Sino-Japanese reading) and 訓読み (native reading), each digit has two readings as well. (English speakers can't complain about this too much: for example, “one”, “first”, “primary”, “single”, “mono-”, and “uni-” all refer to the same number.)
As you dive in, other points of interest reveal themselves: lucky and unlucky numbers; special compounds for certain numbers; and even variant kanji to thwart financial fraud. Today we'll look at the numbers 0 through 10 in a lot more detail. I'm sure some things will be overlooked, but we will at least scratch the surface more deeply.
一 (“one”) is an easy kanji to remember, but in its simplicity lies a problem: it's easy to add strokes to change a written 一 into 三 or 十. Imagine having legal and financial documents altered in this fashion. The Chinese characters for 1 through 9 and several powers of 10 have alternate characters, called Formal, Financial, or 大字 (“upper case”) numerals.
The practice survives in Japan (see the 2,000-yen bank note for an example), though not all digits get the formal treatment. In current use are formal numbers for 1 (壱), 2 (弐), 3 (参), 4 (肆), and 10 (拾).
The Celestial Stems are ordinal numbers that originate from the 10 days of the week during the Shang Dynasty, more than 3,000 years ago. They still see use as ranks and ordinals today in legal documents, student grades, and even highway number suffixes in Taiwan. They seem to be less widely used in Japan than in China.
The numbers 1 through 10 are 甲、乙、丙、丁、戊、己、庚、辛、壬、and 癸. Some characters have non-numeric uses, such as 辛 for “spicy”. The 訓読み for them break down into five “big brother” / “little brother” pairs for the five Wu Xing elements (see 日曜日など, from Feb. 2017). These are:
|1||甲||きのえ||木 の 兄||Wood Big Brother|
|2||乙||きのと||木 の 弟||Wood Little Brother|
|3||丙||ひのえ||火 の 兄||Fire Big Brother|
|4||丁||ひのと||火 の 弟||Fire Little Brother|
|5||戊||つちのえ||土 の 兄||Earth Big Brother|
|6||己||つちのと||土 の 弟||Earth Little Brother|
|7||庚||かのえ||金 の 兄||Metal Big Brother|
|8||辛||かのと||金 の 弟||Metal Little Brother|
|9||壬||みずのえ||水 の 兄||Water Big Brother|
|10||癸||みずのと||水 の 弟||Water Little Brother|
All computer nerds know that lists properly start with zero; still, zero seems to get overlooked in beginning Japanese material. Even the idea of zero itself is a relative latecomer to the Japanese language.
Though 零 meaning “zero” has been around for hundreds of years, lately the import ゼロ is more popular in casual use. Its advantages over 零: less ambiguous when spoken (零 has many homophones); and easier to write.
Originally, 零 didn't mean zero anyway. In Chinese, this combination of 雨 (rain) and 令 (command) meant “a little bit of rainfall.” Around 1248, a Chinese mathematician adopted the symbol to mean zero; later, Japan adopted the same meaning. (I wish I had more information about how and when this happened.) 零 still retains another meaning of “spill, overflow” in words like 零れる. 零 also gets its 音読み from 令.
〇 (まる) is used in some numerals; where English would use “Room one oh five”, Japanese might use “いちまるご”. Chinese also uses 〇 in year numbers; for example, 二〇一八 for 2018 is fine, 二零一八 is less common, and 二0一八 looks weird and wrong.
We're omitting a few words that stand for “nothing”, but not really the number zero, such as 無, ヌル, etc.
壱 is the 大字 substitution for 一; 弌 and 壹 are older 大字 for the same.
一日 has two readings: いちにち for “one day” and ついたち for “first day of the month”. 朔 shares the latter reading, with the meaning “first day of the lunar month.”
一寸, whose meanings include “just a little”, is most often written using hiragana: ちょっと.
独 is not strictly a number, but does mean “single”, “alone”, or (serving phonetically) “Germany”. Its 訓読み, ひと.り, matches 一人, or “one person”. 単 (simple) also has a meaning of “single”, as in 単位 (unit).
弐 is the current 大字 in use for “two”. (It's very similar to 弌, an older 大字 for “one”... however, it's easy to alter 弌 into 弐!) 貳 and 貮 are older 大字 for the same.
Like 一, 二 has special readings for people: 一人 and 二人. Starting with 三人, the 音読み are used for larger groups.
The reading for 二日, ふつか, applies to both “2nd day of the month” and “two days”, without a separate “ににち” reading.
倍 can mean “double”, or serve as a more general multiplier when following another integer.
A few related kanji have similar 訓読み to 二: 両: “both”, ふたつ; 双: “pair”, ふたつ; 再: “twice, again” , ふたた.び.
A fun compound, 二日酔い (”2 days drunk”), means “hangover”. Does a really bad hangover merit “三日酔い”? Yes, it does... but Jisho calls it a colloquialism. Going further, “四日酔い” has some Google hits, but no dictionary entry. There's only so long alcohol can stay in your system.
The 大字 for “three”, unlike the esoteric replacements for 1 and 2, is a 常用 kanji with other common uses. 参 means “to come (or go) [humble]” or “to be defeated”. 参加 is “participation”. 参道 is a road approaching a shrine. Harajuku's fashionable Omote-sandō is simply the shrine road (参道) to the front (表) of Meiji Shrine.
弎 is a rare variant of 三.
四 has a 大字 version (肆), but it's not commonly used, as 四 is more difficult to alter. 酒 and 西 are possibilities, but will not be confused with numbers :-)
四 does seem to be the point where it became apparent that the 一, 二, 三 pattern, however easy it was to master, would eventually not scale up. There's no “亖” kanji in use today... but the original form, written on shell and bone, was indeed 亖. (I haven't seen record of a stacked “five” kanji.)
蓰 is a rare kanji meaning “to increase five-fold”; and I haven't found matching kanji for four-fold and other amounts.
陸, the 大字 version of 六, has a more common meaning of “land”, as in 大陸 (continent) and 離陸 (take off; or literally “detach from the land”).
漆 (lacquer, varnish) is listed as a variant for 七, but I cannot find any examples of this in Japanese compounds.
As the numbers grow larger, there are fewer variants to be found; eight, nine and ten each have the formal and celestial variants, but not much else. Although 8 is a lucky number in many cultures, we won't get into pure numerology here. A few higher numbers with cultural or historical interest, such as 八百屋 for greengrocer, will be covered in a future article.
Like the more famously unlucky number 4 (四 sounds a bit too much like 死, which leads to a preference for the よん reading), 9 has an alternate きゅう reading, since く sounds like 苦, “suffering”.
Though 十 by itself means unambiguously ten, it does serve in some compounds to mean “cross-shaped”, such as 十字路 (crossroads).
Next time, we'll look at some higher numbers, like 廿, 卅, and 阿僧祇. It may not be educational, but hopefully it'll be interesting. またね!