He held an official position in Baghdad during which time he wrote his three main works:

*Al-Badi' fi'l-hisab*(Wonderful on calculation),

*Al-Fakhri fi'l-jabr wa'l-muqabala*(Glorious on algebra), and

*Al-Kafi fi'l-hisab*(Sufficient on calculation).

He was able to develop many of the basic algebraic properties of rational and irrational numbers, and therefore represents an important step in the evolution of algebraic calculus.

Al-Karaji is known as the first author of the algebra of polynomials. Al-Karaji work holds an especially important place in the history of mathematics. Woepcke (historian, Orientalist and mathematician) in 1853 remarked that “it offers the most complete or rather the only theory of algebraic calculus among the Arabs known to us to the present time”.

Al-Karaji employed an entirely new approach in the tradition of the Arab algebraist –al-Khwarizmi, Ibn al-Fath, Abu Kamil commencing with an exposition of the theory of algebraic calculus.

**Abū Bakr ibn Muḥammad ibn al Ḥusayn al-Karajī (980-1030)**