NUMERAL SYSTEMS OF MEXICO AND CENTRAL 
AMERICA 
By Cyrus THomas 
PRIMARY NUMBERS 
Tt 1s well known that the vigesimal system of numeration prevailed 
among the Mexican and Central American tribes, at least among all 
which had adopted the so-called ‘‘ native calendar”’—that is, the cal- 
endar specially referred to in my paper entitled Mayan Calendar 
Systems, published in this volume. Numerous short notices and inci- 
dental mentions of the general system and completer notices of the 
systems of particular tribes are to be found in the early Spanish 
authorities and in the works of more recent writers. As, however, 
most if not all of them are limited in scope, relating to the system of 
but one tribe or people, or referring only to certain points, and as no 
paper devoted specially to the subject of numeral systems has appeared 
in English, it is deemed expedient to, present this paper as a supple- 
ment to those which have preceded it. Moreover, it is believed that 
a résumé of the subject in the light of the recent advance in our knowl- 
edge of Mexican and Central American archeology will be acceptable 
to those devoting attention to the study of prehistoric Mexico and 
Central America. 
As my paper on the calendar systems* related to the time system 
and symbols of the Mayan tribes, and incidentally to the numeral sys- 
tem as used by them in counting time, attention will here be paid to 
the numeral system in its more general application among the Nahu- 
atlan, Mayan, and other tribes of Mexico and Central America which 
used the vigesimal system. 
T have shown in the paper on calendar systems that in counting time 
1 


1 This expression will be used throughout to refer to the paper mentioned aboye, published in this 
volume. 
859 
