They Had A Base 20 Number System And A Calendar With Two Cycles

The Aztecs utilized a base 20 or vigesimal number system to keep track of their numbers. To depict values up to 20, dots or a combination of dots and bars were employed. A flag was used to denote 20 and was repeated for quantities up to 400. A fir tree was used to signify 400, while a sack was used to represent 8000. Though they possessed a mental understanding of zero, it is unknown whether they had a symbol for it, hence 0 was not a common number in their system. Multiplication and division, as well as some geometric ideas, were known to the Aztecs. A land rod, which equaled around 2.5 meters, was their standard unit of linear measurement.

They also utilized symbols like an arrow, a heart, a hand, or a bone to symbolize fractional distances when measuring land areas, according to recent research. The Aztecs had a 365-day calendar cycle called xiuhpohualli (year count) and a 260-day ritual cycle called tonalpohualli (day count). Together, these two cycles constituted a 52-year "century." The agricultural calendar is known as the xiuhpohualli, while the sacred calendar is known as the tonalpohualli. This is considered as one of the major achievements of the ancient Aztec civilization.