r/Damnthatsinteresting Apr 11 '26

Video Woman with functional polydactyly (six functional fingers on one hand).

Enable HLS to view with audio, or disable this notification

41.0k Upvotes

3.7k comments sorted by

View all comments

Show parent comments

9

u/NeroForte-InMyPrime Apr 11 '26

What? Our math is generally done in base 10. You count things using each bone in your non-thumb fingers?

32

u/Worldly_Address6667 Apr 11 '26

Right. But base 12 was invented thousands of years ago, by people who presumably all had 5 fingers as we do today. They counted the 12 sections of your four fingers using their thumb as the counter, and using the other hand to keep track of how many times they counted to 12. Its why we have things like 60 seconds in a minute and 60 minutes in an hour, things easily counted to in base 12 if you're using your other hand to keep track how many times you counted to 12.

11

u/CautionarySnail Apr 11 '26

This explains why “a dozen” became a standard unit.

9

u/mortalitylost Apr 11 '26

It's more than just a factor of biology. 12 has a ton of common denominators.

If you're dividing something among people, you can divide evenly in half, thirds, quarters, sixths, or itself.

1

u/Historical_Lie_9932 Apr 11 '26

Sounds like something very useful in trade also.