numerorum

Numerorum is the genitive plural form of numerus, a Latin noun meaning "number" or "numeral." In Latin grammar, numerus refers to a number or a unit of counting, and numerorum literally means "of numbers" or "numbers." The form is commonly found in classical and medieval Latin, especially in titles and phrases that modify or relate to numbers.

In medieval mathematics, Ars numerorum ("The Art of Numbers") was a conventional title applied to several Latin treatises on arithmetic and number theory. While not a single unified work, the phrase designates a body of texts produced in the Latin-speaking scholastic world from roughly the 12th to the 14th century. These works typically covered arithmetic techniques, properties of numbers, and early methods in number theory, often drawing on earlier Islamic and Indian mathematical traditions as they circulated in Latin translations.

Outside such titles, numerorum occurs as a genitive modifier in many Latin phrases, for example in descriptions of manuscripts or mathematical treatises, or in grammatical discussions about numbers. It also appears in modern scholarly discussions of Latin lexicon to illustrate the use of the genitive plural with numerus.

Numerorum thus serves as a linguistic and historical marker, illustrating how Latin expresses "numbers" and how the phrase entered the naming of mathematical literature in the medieval world.