Which major mathematical idea did the Aztecs develop?

Aztecs were dominant in Central Mexico in the 1300s through the early 1500s.

Their major mathematical ideas:

- They had vigesimal number system (using 20 as its base). For example: 23 = 1 dot + 3 lines

- They had knowledge about multiplication and division and also about certain principles in geometry.

- They estimated land area in parcels that were often irregularly shaped.

- They had standard unit of linear measurement (about 2.5 meters).