Why do Irathients use a base 18 number system and castithans a base 20 number system and they don’t use a base 10 number system like us? I know we use a base 10 system because we have 10 fingers, but Irathients and castithans have the same amount of fingers.

dedalvs:

The Mayans also had ten fingers and they used a base 20 counting system. If it were based exclusively on the number of fingers we had, there would never in history have existed bases other than 10! Plenty of them have existed, though.

Presently, Irathients use a base-20 number system just like the Castithans, because the Castithans imposed base-20 on everyone else (except the Indogenes, who still use base-7 because they think it’s the most logical system). Their previous system was base-18.

And don’t I want to hear any nonsense about base-18 being unrealistic. Frankly, I’m greatly disappointed with humanity for not coming up with base-18, because it’s sooooooooo obvious how you would do so. Are you ready for it? Because I’m going to show it to you right now. And you and all the doubters out there will be flabbergasted at how unbelievably simple it is to come up with a base-18 counting system. I hope you’re prepared.

Here it is:

image

And that’s that. You use your off-hand to count, you switch when you get to ten, and counting goes very quickly.

(Honestly, though, these hands are backwards. It should be the pinkies on the inside, not the thumbs. But beggars can’t be choosers when it comes to clip art.)

So that’s how the Irathients came up with a base-18 counting system. Not a different question: How are we humans so stupid that not a single one of our lazy civilizations came up with this simple—indeed, superior—counting system?! We all have ten fingers and eight in-between finger spaces. What’s the deal?

Didn’t the Babylonians have a base 60 system because they could count to 12 on one hand and 5 on the other? See: https://en.m.wikipedia.org/wiki/Sexagesimal (sorry, Tumblr mobile fails when trying to insert a link)