calculus
cal.cu.lus \-l*s\ \-.li-, -.le-\ n or cal.cu.li also cal.cu.lus.es [L, pebble, stone in the bladder or kidney, stone used in reckoning] pl 1: a concretion usu. of mineral salts around organic material found esp. in hollow organs or ducts archaic 2: CALCULATION 3a: a method of computation or calculation in a special symbolic notation 3b: the mathematical methods comprising differential and integral calculus