One of the earliest mesoamerican civilization were the Olmecs who lived in southern Mexico from 1500 BCE to 400 BCE. This civilization were the earliest civilization in Central America to develop a writing and mathematical system. Their mathematical system included the number zero.
Other early mesoamerican civilizations include the Maya who lived in parts of Mexico, Belize, Guatemala, parts of El Salvador and Honduras. Their civilization began around 2000 BCE to present. One of the most famous structures built by the Maya was the Caracol in Chichen Itza. The Caracol was built in 1000 CE as an observatory to study the stars, moon, and planets. The intense study by the Maya allowed them to build the Caracol in perfect alignment to the patterns of the planet Venus.
The mathematical system developed by the Maya was a base-20 system with no zero and no fractions. Their system include tables used for calculations. The Maya relied heavily on their elaborate calendar system that calculated future calendar dates, very far into the future. The famous Maya calendar calculated the end date to a 5,126 year long cycle to occur on December 21, 2012. That end was seen by many in the modern world as mystical event perhaps leading to world wide catastrophe. The Maya made one of the most complete understandings of time with the development of their calendar system.
The Aztecs developed a length units called maitl (the distance from outstretched fingertip to outstretched fingertip) and yolloti (meaning heart the distance from outstretched fingertip to center of chest). The Mayas where advanced in their measurement of time, developing a complex calendar system. Today we know the length of a year is 365.2422 days or 365 days, 5 hours, and 48 minutes. The Mayas had this measured length of a year almost exact (off by 1 minute). The Maya Pyramid of Kukulkan at Chichen Izta, built in 1050 has four stairways, each with 91 steps and a 1 step platform on top making a total of 365 steps!
Archaeological discoveries have found clay bowls of equal volume and equal divisions of one volume. Many goods traded in early markets were determined by a measurement of volume over a measurement of weight.