Brahmagupta, a Hindu mathematician and astronomer, first used a dot underneath other numbers to represent the number zero in 628 A.D. He was the first to develop additive and subtractive operations that use zero.
In India circa 458 A.D., other words were used to represent zero, but at that time, math equations were chanted, spoken poetically or spelled out instead of using symbols. Brahmagupta's idea of zero became part of the Arabic number system in 773 A.D., when a Persian called Mohammed ibn-Musa al-Khowarizmi decided to make the symbol for zero be a circle. He used it to create algebra in the ninth century.