Over time, "algorism" was largely replaced by the word " algorithm " due to a "pseudo-etymological" confusion with the Greek word arithmós (number).
Official METAL FORTH Song Discussion Thread - Track 8 [Algorism] algorism
The word is a Latinization of the name of the 9th-century Persian mathematician al-Khwarizmi , whose work introduced decimal arithmetic to Europe. Over time, "algorism" was largely replaced by the