Gould notes that the Maya, who achieved a high level of civilization by the 5th century AD, were different, using a base 20 system. He suggests, amusingly, that they also counted their toes.
古爾德還幽默地指出，紀元五世紀時便已發展出高度文明的馬雅人大概把十個腳趾頭也加入計數，所以採用的是二十進位法。