what is a weighted average?

    Before you get too deep into analyzing your grade, you need to know that it gets calculated according to a weighted average. Since this system is different than the one a lot of teachers use, you may need to see an explanation of what that means.

    As a simple example, suppose that you only had two types of math scores: homework and tests. It might be that your teacher wants your grade to be built in a specific relationship between homework scores and test scores ... for example, that homework is 60% of your grade and that tests are 40% of your grade.

    If the teacher just goes by total points, he can't guarantee that the balance between the categories will be what he wants it to be. If, in one chapter, there are six twenty-point homework assignments and an eighty-point test, the balance is 60:40. But if the next chapter has five thirty-point homework assignments and a fifty-point test, the balance is 75:25.

    To guard against that, some teachers (like me) use grade weighting. Instead of lumping all of your scores together, teachers who use grade weighting actually first give you a grade for each category and then put them together in the right relationship. With the example we've been using, you'd get a homework grade and a test grade. Your homework grade would then be multiplied by 0.6; your test grade would be multiplied by 0.4. Finally, those results would be added to give your overall grade in the class.

    The system is a little more complicated for the student, and a little more work for the teacher, but it's the best way to insure that your grade has the balance that the teacher wants. No matter what homework gets assigned, no matter how tests get written, the grade will always be 60% homework and 40% tests.