(7) Is there another way to write Mayan numerals?
Mayan numerals appear in codices found in the Mayan ruins. They can be represented by shells, dots, and lines like they are in the Leyden plate from the article at mexconnect.com either in vertical or horizontal form. The Leyden plate, like many other stone plates (estelas) were made to commemorate important dates or events. They were either engraved or painted. Numbers can also be represented by head glyphs. In “The Numerical Head Variants and the Mayan Numbers,” by Macri, the author concludes that the head variants are phonetic representations of the numbers.