Homework/lab reports/attendance account for 20%.

It is natural to assume that the class follows normal distribution (the bell-shape). Hence, the cut-off points will be determined according to the class distribution. The cut-off point between an A and a B may be 85 points in the midterm but it may be 90 in the final, for example.

You can keep track of your current score and find out approximately where you stand in the course from the webpage.