The 3 groups all made technological advancements in areas like mathematics, construction, and astronomy. The Mayans used a positional numerical system that included zero. The Inca used a base-10 system to record information on quipus, which were strings and knots. The Aztecs used a base-20 numerical system knows as the vigesimal system. The Myans built observatories to study the bodies and many different things. Shortly after that they made a calendar system. The Aztecs used they sky to create a calendar system that predicted solar and lunar eclipses. The Inca used the movements of the sun, moon, and stars. They built different structures and the way they taught was different but all ended up helping them economically and turned into a structured civilization.