calculus, n.Definitions

Calculus is the Mathematics of change

Calculus is when letters decide to be numbers.

Calculus is the art of thinking of curvy lines as straight lines at each point.

Calculus is the most significant factor in the development of modern science beyond where it was in the days of Archimedes.

Calculus is the study of change by studying "instantaneous " change, by which we mean changes over tiny intervals of time.