The Maya of Central America used a mixed base 18 and base 20 system, possibly inherited from the Olmec, including advanced features such as positional notation and a zero.
Mayas wən Amérique tanamas adakalan əmik ertayan dǎɣ santo ən 18 əd dǎɣ santo ən 20, amosan adizgaran dǎɣ Olmequetan, ahan talɣiwen azarnen atamosnen asiɗin ən dagan əd wala.