Little attention has been paid to the methods the Maya may have employed in calculating dates in their complicated calendar, although Cyrus Thomas displayed some interest in the matter.^{1} A knowledge of the system actually used is not a matter of merely academic interest, for if we are ever to achieve a comprehensive reconstruction of Maya culture, we must have some insight into Maya mental processes. I have previously touched on this question in an attempt to follow Maya patterns of thought.^{2}
In this paper, a working knowledge of the Maya calendar is assumed. Readers who lack this introductory grounding are referred to Bowditch, Morley, Thompson, Palacios, or Teeple.^{3}
Many methods, involving the use of tables, multiplication, division, or even slide rules, have been devised for the use of the presentday student of the Maya calendar. These are extremely convenient, enabling the positions of Maya dates (there are 18,980 combinations of day and month in reentering sequence) to be rapidly calculated, but of course they make no pretense of being patterned on the methods used by the Maya mathematician (if one can accord him such rank). Indeed, there is ample evidence in the Dresden Codex that Maya arithmetic never embraced multiplication or division but achieved results solely by addition and subtraction. The method is clearly shown in tables from the Dresden Codex, which will be discussed, and needs no elaboration here.
Furthermore, Diego de Landa hinted that counters of some sort were used, for “they count on the ground or on something level.”^{4}



Main web site: http://www.pauahtun.org