Professors utilize a variety of assessments, such as tests, quizzes, homework, projects and oral presentations to evaluate student mastery of subject matter. The various assessment scores are aggregated to arrive at a course grade. Different methods of aggregation can result in different course grades. This paper outlines the nature of the differences using illustrative examples and demonstrates the disparities that result from applying different aggregation methods on actual data for more than 1,000 students in accounting classes. Possible modifications to grading schema that would reduce disparities and implications for course design, for student motivation and for faculty-student communication, are also discussed.