The way base 12 would work is that you’d add 2 characters and you would write “12” as 10. Which looks really confusing because we’re all used to base 10. If you were then to do 1010 in base 12 (so in base10 that would be 1212) you’d get 100 (144 in base10) so this still stands whatever base you use.
Actually this works fine in base 12 too! See my other comment for a more in-depth explanationz