History for Kids: Aztecs, Maya, and Inca. Repinned by Elizabeth VanBuskirk on "Teaching about the Incas." A good way to visualize the difference between Inca (South America), Maya (Central America) and Aztec (Mexico).
Mayan Mathematics - The Mayans had one of the most advanced number systems in the world at its time. It was a base-20 system (kind of) that also relied quite heavily on the number five. Some think that this is due to five fingers and five toes on each hand and foot. Their system relied on three different symbols. A “pebble” (small black circle) was used to represent the ones place. Learn more: https://3010tangents.wordpress.com/2015/02/25/mayan-mathematics/