Yup, I've felt that way at times. My DS is a sophmore in H.S. and there I times I've felt this way. Depends on the teacher and administrator I'm stuck with at the time. 8th grade science was one of the classes that had me feeling this way.
Curious what math books/program you son is using? There are some really dreadful books out there right now. Your son is going to have to learn to "show his work" but some of these are insisting on showing your work when none is really necessary. One way to explain this to your son is once he has finished the work, he should go back and explain how he got his answer as if he was teaching a struggling student.
