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 ).

Morning. sorry sjznzbz