The numeration, calendar systems and astronomical knowledge of the Mayas
"They (our ancestors) used (for numerals in their calendars) dots and lines back of them; one dot for one year, two dots for two years, . . . in addition to these they used a line; one line meant five years, two lines ten years; if one line and above it one dot, six years. . . . " Charles P. Bowditch, 1910, quoting Daniel Garrison Brinton, 1882.
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One dot for one year; one line for five years