Algorism

Algorism is the technique of performing basic arithmetic by writing numbers in place value, or positional, notation and applying a set of memorized rules and facts to the digits, and a person who practices this method is called an algorist. This positional approach to calculation gradually displaced earlier methods such as counting with Roman numerals or working directly on an abacus. The word algorism, and ultimately the modern word algorithm, derives from the name of Muhammad ibn Musa al-Khwarizmi, a Persian scholar active at the House of Wisdom in Baghdad around 780 to 850, whose name indicates he came from Khwarezm in what is now Uzbekistan. His ninth century Arabic treatise on Indian methods of calculation was translated into Latin in the twelfth century under the title Algoritmi de numero Indorum, and the Latinized form of his name gave rise to the term. English adopted the word around 1230, and Geoffrey Chaucer used it in 1391; in the seventeenth century French scholars respelled it as algorithm by analogy with logarithm, a spelling English later followed. Al-Khwarizmi and other medieval Islamic mathematicians extended Indian base ten arithmetic, documented new computational procedures, and introduced decimal fractions, laying groundwork that Leonardo Fibonacci later used to popularize the Hindu-Arabic numeral system across Europe.