This paper describes two uses of the software package TEMATH (Tools for Exploring Mathematics) with calculus students: (1) as a demonstration tool in the classroom to visually explore with students the many mathematical models introduced in a first year calculus course; and (2) as a part of a lab where students use a set of laboratory explorations to experiment on their own and write down their findings, interpretations, and conclusions. Guidelines for presenting a successful classroom computer demonstration are given, as well as examples of assigned explorations and activities. These activities include sequences of secant lines, parametric equations, using real data, modeling the men's summer olympics gold medal long jump distances, numerical integration, the derivative as a function, and Taylor polynomial approximations to the circle. (MKR)