The Mayan and other Mesoamerican cultures used a vigesimal number system based on base 20 (and, to some extent, base 5), probably originally developed from counting on fingers and toes. The numerals consisted of only three symbols: zero, represented as a shell shape; one, a dot; and five, a bar. Thus, addition and subtraction was a relatively simple matter of adding up dots and bars. After the number 19, larger numbers were written in a kind of vertical place value format using powers of 20: 1, 20, 400, 8000, 160000, etc (see image above), although in their calendar calculations they gave the third position a value of 360 instead of 400 (higher positions revert to multiples of 20). The Maya themselves did not invent writing, but they did develop the most complex mixed-scripture writing system called Logo Syllabic, made up of over 800 glyphs. The origins of Maya writing may be traced back to the south of Mexico , to a place called Veracruz , as well as to Guatemala 's and El Salvador 's Pacific Coast. The people who lived there, the Olmecs or Mihezoke people, painted these first glyphs at Tres Zapotes around the year 29 BC, this was the first evidence of written language in ancient America
