If you're interested in languages or are from Scandinavia, you have heard of Danish numbers. The Danish numeral system is my favourite example of how language can be beautifully insane.
Let us illustrate with the Danish word for 50. Halvtreds.
Halvtreds is literally "half-third". You may ask, how the fuck do you get 50 from "half-third"?!
Ah, but halvtreds is actually an abbreviation of halvtredsindstyve... literally "half-third times twenty". We are still baffled, because (1.5 * 20) is definitely not 50.
But it turns out that half-third works like Roman numerals! Just as we write IV = (5 - 1) to represent 4, halvtreds means (3 - 0.5), or, (2.5).
If you do the math, 2.5 * 20 is actually 50!
Languages are beautiful, aren't they?