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.he Mayan civilisation had settled in the region of Central America from about 2000 BCE, although the so-called Classic Period stretches from about 250 CE to 900 CE.