We work with numbers from 1 to 10, and you pass if you get a 5,5 or higher. Because every grade gets rounded to a whole number. Every question is worth a certain amount of points. During normal tests, the grade is simply {points earned * 10 / maximum points}. During the exams the grades are a bit harsher, you would get a 6,0 for your exam if you'd get a 7,0 if it was a normal test (roughly).