In Finnish, the numbers 11–19 are (the number for 1–9) + “toista”, lit. “of the second (ten)”. So 11 is yksitoista, “one of the second (ten)”. That system is only used for 11–19. Bigger than that is tens + number, e.g. 21 kaksikymmentä yksi (two tens and one).
The Finnish word for “teen” is “teini”, which is a loanword from English. The native word for a person that’s not a child nor an adult is “nuori” lit. “a young”.
Japanese is 1 (ichi), 2 (ni), ...,10 (juu), 10+1 (juu-ichi), 10+2 (juu-ni), ..., 21 (ni-juu-ichi)..., 92 (kyu-juu-ni)..., 100 (hyaku)
Yeah, the numbers look all nice and orderly in the abstract until you need to use them for something in the real world...
