BBNBI uses the following method to compute the overall course grade:

First, all of the individual lesson test grades are averaged together, and that average is counted  for 20% of the overall grade. Then the Final Exam grade is counted as 80% of the overall course grade.

Example: If the course has 4 lessons: lesson grades were 50,65,83,100; average of these is 74.5 (rounded up to 75) then the Final exam grade is 100; so we take 75 times 2 = 150 and the 100 times 8=800; then add 800+150= 950 and divide it by 10= 95 So the overall course grade is 95

The computer rounds off all grades.