The cossist tradition was a school of abacist mathematics developed in Germany in the 15th century.
Notable cossists include Johann Faulhaber.
The word can be found in the title of Robert Recorde's 1557 work:
- The Whetstone of Witte, whiche is the seconde parte of Arithmeteke: containing the extraction of rootes; the cossike practise, with the rule of equation; and the workes of Surde Nombers.
The word cossist originates from the Italian cosa (thing).
- 2009: Ian Stewart: Professor Stewart's Hoard of Mathematical Treasures: Who Invented the Equals Sign?