In Portuguese middle-schools, a five-point grading scale is used, where:

• 5 (very good or excellent) is the best possible grade (90-100%),
• 4 (good) (70-89%),
• 3 (satisfactory) indicates "average" performance (50-69%),
• 2 (unsatisfactory) (20-49%),
• 1 (poor) is the lowest possible grade (0-19%).

In high-schools and universities, a 20-point grading scale is used. When it is the case of the final grade of an academic degree, each grade is assigned a qualitative mark by degree (depending on the university, the students have at most a final grade of 16 or 17, being almost impossible for students to have a final score between 18-20): ^[1]