Al-Khwarizmi wrote about the practical use of decimals and also clarified and popularized a method for solving certain mathematical problems. He explained the method in his work The Book of Restoring and Balancing. The term al-jabr in its Arabic title, Kitab al-jabr wa’l-muqabala, is the source of the English word algebra. Algebra, says science writer Ehsan Masood, is considered “the single most important mathematical tool ever devised, and one that underpins every facet of science.”a

“Countless generations of high school students wish [al-Khwarizmi] hadn’t bothered,” quips one author. Be that as it may, al-Khwarizmi stated that his aim was to explain methods in order to simplify calculations in trade, the division of inheritances, surveying, and so on.