¿Wait what?

In Swiss French we say « septante » (70) « huitante » (80) and « nonante » (90) which is better than counting by 20

English used to do this too. The most famous example is the first line of Lincoln’s Gettysburg address:

Four score and seven years ago our fathers brought forth on this continent, a new nation, conceived in Liberty, and dedicated to the proposition that all men are created equal.

as someone who gave up on learning french because of those shenanigans, i feel validated

I love that song!

More like:

// German
Farbe = "#(9&90)FFAA";

As a programmer and a linguist, this is the kind of content that really gets the happy chemicals flowing through my monkey brain

Jokes aside, #9FA actually works too.

#99FA9FFA9FAA?

https://en.wikipedia.org/wiki/Farbrausch

Joke aside, it's not taught as 4 × 20 +10 but simply “90 is pronounced quatre-vingt-dix” — which kinda is a mouthful, but you rarely count to 90 as a kid anyway.

Whole generations of French students that have no idea they escaped having to write "mille neuf cent quatre-vingt dix-neuf" over and over again, in cursive of course.

Nineteen is dix-neuf though. Which is literally ten-nine. 11-16 all have an equivalent word to the English “teens.” Quatorze for example instead of dix-quatre for 14.

Takes notes

Next time meeting someone who might speaks french: Pontjur fellow frenchman, i need cat wank deez nutz of those poms

Well, there isn't a word for 99 in Spanish or English, in both languages we say 90+9, so that counts as maths.

If you are asking about words for 70, 80 and 90, that is a peculiarity of French, and not even all dialects, some dialects have septante, huitante/octante and nonante for those.

haha no

It's just the French being weird, there's even some non-France French dialects that count normally.

The Spanish might talk too fast to understand anyway, though.