1 2 3 4 5 6 7 8 9 10 11 12 Counting to twelve in base 10
1 2 3 4 5 6 7 8 9 A B 10 Counting to twelve in base 12
I think a duodecimal(base 12 system) would be more efficient than base 10. At least I think money should be this way. 5's, 10's, 50's are all sucky bills. Hurrah for the three dollar bill!