Of course we'd have had 12 unique symbols if humanity had adopted base 12 instead of base 10, say if that would have happened historically with arabic numerals

Of course we'd have had 12 unique symbols if humanity had adopted base 12 instead of base 10, say if that would have happened historically with arabic numerals (but it's a bit more complicated historically of course because the roman numerals and other systems before it were already decimal, even the babylonean base 60 was actually decimal based anyway, their notation uses 6x 10 symbols, not 5x 12 symbols). Obviously it didn't and history won't change :) And yep, no matter in what numeric base you are, "10" will represent the amount of symbols of that base. "10" in binary is 2 in decimal, "10" in hex is 16 in decimal, etc...