Explanation:
if if you have completed the two lessons and the two lessons are overdue. your grades on the two completed lessons are 80% and 90% so your score to date would calculate to 80 + 90 = 170 now divide 170 / 4 (lessons) 170 / 4 = 42.5% deprogresses your progress in the course indicated by progress bar and percent complete.
I hope this helped
