Well, the classes here go either by semesters, twice a year, or by quarters, 3 a year. At the end of the semester/quarter, there is an exam that gives a score from 5 to 1, with 5 meaning the greatest and 3 as passing the class. The exam is what makes up your credits.
But the rest, all hail breaks loose. Since the professors are krappy as hail, they can't teach but you will have to go by their rules. They decide on whether to have midterms, composition, etc......