I get asked this question periodically and so I thought I’d share my thoughts. Feel free to post comments or questions!
Why are grades given in the first place? They are a communication tool — a short-hand way of letting others know how well a student is doing at mastering the content of a given course. One of the main interested parties is the student himself! Whether in a classroom or homeschooling, most students want objective feedback to monitor their progress. Boys especially are motivated by grades (even more so when dad takes notice!).
Grades in a school setting are closely monitored by parents to know how their child is doing, but obviously that is not necessary for a homeschooling family.
Grades communicate to colleges. We should be honest and careful in reporting grades and not just assign all “A’s” because we can, and to make our child “look good.” If they struggled with Algebra 2, their grade should reflect that. If they skimmed through Chemistry and really didn’t understand much of it, a C would be more honest than an A-.
Everyone instinctively knows what letter grades should mean — A implies good mastery, B communicates that the main concepts were nailed, but there were areas of struggle, while a C or D indicate gaps, struggle with understanding, and perhaps a lack of serious effort. Adding a plus or minus behind the letter helps tweak the grade.
Some homeschooling parents like to administer tests, quizzes, and homework assignments and then average the grades to get a percentage score. That’s fine, but not necessary, though with some students just knowing that “everything counts” toward their grade helps motivate them to do better! Other parents prefer to give a letter grade at the completion of the course. Either way is fine with me, but I do highly recommend assigning some type of grade for all courses in 9th-12th grade. Colleges expect grades on the transcript.
In a separate post I will suggest a grading scale for you to consider using.
My conclusion: Give grades — number or letter — at least at the end of every course for the sake of those looking at the transcript. Calculate and report grades more frequently if that helps motivate your teen.