Final answer:
The Sumerians were skilled in multiplication, division, and fractions, and developed complex arithmetic systems based on 60, 10, and 1, but they did not invent calculus or decimals.
Step-by-step explanation:
The Sumerians made significant advances in mathematics, which included capabilities in multiplication, division, managing fractions, and developing a number system based on the numbers sixty, ten, and one. They did not, however, develop calculus or decimals as those were contributions made later by other civilizations. The Sumerians were known for their complex arithmetic system, which was highly influential in the ancient Mediterranean world. They also created the 360-degree system used for measuring angles in geometry and a system of timekeeping with a 60-second minute.