Aryabhatta was a famous Indian mathematician and astronomer from the 5th century CE. He wrote the Aryabhattiya, which introduced concepts like zero, pi, and the sine and area formulas. He was the first to say that the Earth is spherical and rotates on its axis. Aryabhatta made many advances in mathematics and astronomy that were centuries ahead of their time and influenced cultures around the world. Calculus is the mathematical study of change and is used today in physics, chemistry, biology, economics and other fields.