The Gunning Fog Index of readability indicates both the average length of words and the difficult words (three or more syllables) in written material. This document describes a business communication course at Wayne State University in which students calculate the Gunning Fog Index of two of their writing assignments with the aid of the university's computer. This activity provides variety in the course and warns students when their writing is difficult to read. A step-by-step procedure for calculating the Gunning Fog Index by using four computer programs is described. The four programs are appended. (RL)