McClung, William Nebraska Wesleyan University Math/CS Dept. Lincoln, NE 68504-2796 mcclung@nebrwesleyan.edu Exploring Numbers Burton, in his text, Elementary Number Theory, states that "nowhere else in the mathematical disciplines is rigorous proof so often preceded by patient, plodding experiment." I am working on a one-semester number theory text, Exploring Numbers, in which Mathematica will transform "patient" into "exciting" and "plodding" into "thorough" and "far-reaching." It will provide an experimental testbed in which the students will, in a guided fashion, examine numeric evidence to "verify," disprove, and generate conjectures. (Perhaps one measure of the success of this approach is the number of entirely student-generated conjectures.) Proofs of theorems would be attempted only after such experiments. After students become familiar with a few Mathematica number-theoretic primitives, problems of the form "prove or disprove" could be assigned with students expected to generate appropriate experiments on their own. (Due to Wolfram Research's on-line library, MathSource, and the power of Mathematica's programming language, it is not difficult to provide easy-to-use primitives beyond those built in to the program.) While the course described is for math majors, number theory provides a familiar domain to all, and it is anticipated that the experiments could be successfully performed by a much larger audience. Thus a variant of this course for liberal arts students, deemphasizing student construction of proofs, could easily be fashioned. .