Brahmagupta
The rules for calculating with zero and negative numbers are written down.
- When
- Known to
- ± 2 years
- Era
- Post-Classical, Holocene
In 628 CE Brahmagupta gives the first systematic treatment of zero as a number in its own right and states rules for arithmetic with negative quantities, which he describes in terms of fortunes and debts. He also solves quadratic equations including negative roots, gives a formula for the area of a cyclic quadrilateral, and works on indeterminate equations. He gets division by zero wrong, which is fair enough.