Instructors of 41 Navy electronics "C" courses were presented with a list of 70 mathematics skills and asked to indicate: (1) how important they were to successful course performance, and (2) whether required skills were prerequisite to, reviewed in, or taught in the course. Based on results obtained, a mathematical skills test was developed for the "C" course for the Aviation Electrician's Mate and Avionic Technician (AE/AV) ratings, and administered to entering and graduating students. Significant differences were found between the two groups on total test and in seven topic areas, most of which were taught during the course. Since student performance in both groups was only marginal in most topic areas considered critical for successful course performance, it is possible that either the importance of these skills is overrated or criteria for successful course completion are too low. (Author)