Story
Brahmagupta of Bhillamala wrote the Brahmasphutasiddhanta in 628 CE. It is the first known text to treat zero as a number in its own right and to give rules for calculating with zero and negative numbers.
Key contributions
- Gave rules for arithmetic with zero, positive ('fortunes') and negative ('debts') numbers
- Brahmagupta's formula for the area of a cyclic quadrilateral
- Solved quadratic equations and studied the equation now called Pell's equation