I think it means, (from tlactli , half); and this would mean, not the halving of a hand, but the half of the whole person, which you get by counting his hands only. The syllable ma , which means “hand,” makes its appearance in the words five and ten, and no where else; just as it should do. When we come to twenty, we have cempoalli , “one counting;” that is, one whole man, fingers and toes—corresponding to the Vei word for twenty, “a person is finished.”
I think we need no more examples to show that people—in almost all countries—reckon by fives, tens, or twenties, merely because they began to count upon their fingers and toes. If the strong man who had six fingers on each hand, and six toes on each foot, had invented a system of numeration, it would have gone in twelves, nearly like the duodecimals which our carpenters use; unless, indeed, he had been stupid after the manner of very strong men, and not gone beyond sixes. We see how the Romans, though they inherited from their Eastern ancestors a numeration by tens up to decem, and then beginning again undecim, &c., yet when they began to write a notation could get no farther than five—I., II., III., IV., V.; and then on again, VI., VII., up to ten, from ten to fifteen, and so on.