In the 9th century, the Persian mathematician Muḥammad ibn Mūsā al-Khwārizmī wrote several important books on the Hindu–Arabic numerals and on methods for solving equations.
No século IX, o matemático persa Muḥammad ibn Mūsā al-Khwārizmī escribiu varios libros importantes sobre os numerais indoarábigos e en métodos para solucionar ecuacións.