There are a few surviving codices (books) from the ancient Mesoamerican cultures that have accidentally survived. These codices are important documents because they are a kind of almanac. They describe the old rituals, hunting practices, when sacrifices were to be held, and when crops were to be planted and harvested. (Here is more information and pictures from the Borgia Codex.)

When the Spanish arrived and found the codices they burned any of them that they could get their hands on. The Spanish who were Christian believers burned the writings because they did not believe the Mesoamerican people should worship gods and give sacrifices as was mentioned in their books. The Spanish priests wrote that it was Jesus who gave the only sacrifice according to the Christian belief. The Spanish also wanted to force the people of believe in their Christian god and not their many gods but the people of Mesoamerica did not want to and they rebelled.

The Mayas used a very complicated math system and they used the stars to calculate the number of days in a year. They also calculated the days and months by using bars for "5" and dots to represent "1". They also invented a symbol for "zero". For example a number that would now have to be written 146 times followed by 36 zeros in a more primitive system was for the Maya mathematicians a simple combination of dots and bars.

The Mayans had three wheels to represent their calendar. The first one was the days of a month. The second one was the months in a year. and the third one was years in a century. We hope you can see that it took a lot of work just to create the Mayan calendar and without their work in mathematics this would not have been possible.