Al-Kharizmi ( Abū ʿAbdallāh Muḥammad ibn Mūsā al-Khwārizmī) ( 70-850) Claimant of excellence among medieval Muslim scientists. He was simultaneously a mathematician , a geographer and an astronomer. His full name is Abu Abdullah Muhammad Ibn Musa Al Kharizmi. He presents the first systematic solution of linear and quadratic equations in his book Al-Jabbar wal Muqabala by Khwarizmi. His major breakthrough in algebra was the solution of quadratic equations with the help of squares , for which he provided geometric evidence. He was the first to introduce algebra as an independent branch and to discuss the method of solving equations , so Khwarizmi is called the father or founder of algebra. The word algebra (algebra) comes from the title of his book Al Jibar wal Muqabila. Its name is derived from both guarismo ( Spanish) and algarismo ( Portuguese) , both of which mean numbers. In the twelfth century, the Western world introduced the decimal number system based on the Indian numerals described in his book Algorithmo de Numero Indorum . The book Al Jibar wal Muqabila, translated by Robert of Chester in 1145, was the leading textbook on mathematics in European universities until the sixteenth century. Also one of his most famous works is to revise Ptolemy 's book Geography . He listed the latitudes and longitudes of different cities and regions in this book. He also made some astronomical tables and worked with calendars , sundials , and astrolabes.