Or Danish where 90 is halvfems or (5 - 1/2) * 20

... which is especially embarrassing because they got rid of the problem in Swedish and Norwegian.

With one small exception in Swedish. We still do it backwards for some numbers in the 10-19 range. 13 = tretton (three ten), 14 = fjorton (four ten), and so on.

95 could be spoken as "fifteen and four score" in English, and I'm told my great grandfather did this, though people thought he was old fashioned.

It would not be the Danish "five and half the fifth score" though. This is crazy.

There’s a joke in French:

What is 20*4?

Answer: 80 because multiplication is commutative.

Yet, Commutative Algebra is a German invention.

French is not actually that weird; it's just weird from 80-99. From 10-79, it's just like English handles it. They just never came up with single words for 80 and 90.

I think various french speaking regions outside France do use single words for those. E.g. in neighboring Switzerland I learned 70, 80, and 90 as septante, huitante and nonante if I remember correctly (I'm from the german speaking part)

Yes, they do. Belgian French has "nonante", for instance, which would be better, but which just never caught on in "standard" French. It appears in my Cassell's French Dictionary, but it's marked "dial." for dialect.

But they actually did! Septante, huitant/octante and nonante are real French words. Only the French don't want to use them.

Note that you cannot use heptante for septante.

It's also weird for 50-59. English does not say "fourty twelve" ("quarante-douze").

Neither does French, you're confusing 50 with 70. https://frm.wiktionary.org/wiki/quarante-douze

Edit: 50, not 60.

At least in Belgium we fixed that with "septante"

But making things completely logical would have been too much for us so we kept quatre-vingt.

It's weird form 70-79 as well! To say 79, you need to say sixty-ten-nine!

Yeah but I'd never blame someone for telling me "nonante", the Belgian (and more correct latin) variant.

> Four score and seven years ago our fathers brought forth, upon this continent, a new nation

nonante!