Final answer:
The classic Mayan civilization had achievements in mathematics, astronomy, engineering, and architecture. They created an accurate calendar and a written mathematical system. They also built impressive cities and structures that still exist today.
Step-by-step explanation:
The achievements of the classic Mayan civilization include advancements in mathematics, astronomy, engineering, and architecture. They developed an accurate calendar based on the seasons and the solar system. Their mathematical contributions include a written system to record crop yields, population size, and trade. They also built magnificent cities, stone pyramids, and temples, some of which still remain today.