Section 2: Numbers

Japanese numbers work similar to English in small numbers, giving a digit and then its place value. However, there are numbers with multiple pronunciations, as well.

いち 1 に 2 さん 3 よん or し 4 ご 5
ろく 6 なな or しち 7 はち 8 きゅう or く 9 じゅう 10
じゅういち 11 じゅうに 12 じゅうさん 13 じゅうし or じゅうよん 14 じゅうご 15
じゅうろく 16 じゅうなな or じゅうしち 17 じゅうはち 18 じゅうきゅう or じゅうく 19 にじゅう 20
さんじゅう 30 よんじゅう 40 ごじゅう 50 ろくじゅう 60 ななじゅう 70
はちじゅう 80 きゅうじゅう 90 ひゃく 100 せん 1,000 まん 10,000

For large numbers (above 10,000), each power of 10,000 (10,000, 100,000,000, et cetera) has a different word, but words for 10, 100, and 1,000 remain the same and are added to the 10,000 word, even when multiplied by ten thousand. For instance, 123,456,789 would be いちおく(100,000,000)にせんまん(20,000,000)さびゃくまん(3,000,000)よんじゅうまん(400,000)ごまん(50,000)ろくせん(6,000)ななひゃく(700)はちじゅう(80)きゅう(9). However, numbers this big would likely just be written in Arabic numerals like in English.

Some digits also affect the pronunciation of the following place value. For instance, 300 would be さんびゃく, changing the h of ひゃく to a b. Similarly, in 800, はっぴゃく, the h is changed to a p.