We present the results of comparing various ways of calculating students' final grades from continuous assessment grades. Traditionally the weighted arithmetic mean has been used and we compare this method with other alternatives: arithmetic mean, geometric mean, harmonic mean and multiplication of the percentage of overcoming of each activity. Our objective is to verify, if any of the alternative methods, agree with the student's performanceproposed by the teacher of the subject, further discriminating the grade between high and low learning outcomes and reducing the number of approved opportunists.