[301] Calcŭlus (lat.), Stein, Rechenstein, Rechnung; error in calculo, Rechenfehler.
Eisler-1904: Calculus philosophicus
Herder-1854: Calculus Minervae · Calculus
Kirchner-Michaelis-1907: Calculus Minervae
Lemery-1721: Calculus humanus
Meyers-1905: Calcŭlus
Pierer-1857: Calcŭlus