The Egyptians also used a symbolic number system but their system was not positional thus it does not use or required zero to prevent misinterpreting the value.
The Native North Americans used a numeration system of various bases; however, there is no indication of place values or use of zero. The Mayans of Central America and southern Mexico used a positional, vigesimal system. They showed the number zero in the symbol shaped like a half-closed eye which was found in early calendars. The Incas of Peru uses a decimal system that uses different types of knots as well a position of knots to indicate value. The Incans showed zero by indicating a gap between sets