The zero symbol first appeared around 2000 B.C. when the ancient Babylonians used it to mark that something was missing. As a concept and a number, however, the zero was invented in India around 650 B.C.
Brahmagupta was the first person to formalize arithmetic operations using zero. He placed dots under numbers to represent zero, calling them "sunya," which means empty, or 'kha," which means place. He also wrote the standard rules for reaching zero through addition and subtraction, as well as the results of any operations with zero. It would take until 879 A.D. for the number zero to make it to Europe and become the oval shape used today.