Answer:
Making of calender with the help of mathematical system was the astronomical advancement attributed to Mayans.
Step-by-step explanation:
With extensive knowledge on agriculture Mayans were able to understand the prediction of rainfall which in turn helped in grains to grow well. The prediction of rainfall was highly dependent on sun and moon phases.
This co-relation helped Mayans to go deeper in research and understand astronomy in detail. Mayans are known to make the most accurate calendar using the mathematical system. It was the most notable achievement. The Mayans were able to understand the celestial bodies with the help of mathematical calculation and this led to the concept of Calendar.