According to the student guide about viewing grades ( How do I view my grades in a current course?  ), students "may be able to see small changes with assignment shading indicating that a grade may be dropped from the course." I create a couple of assignments in a group that would drop 1 lowest score, then I viewed them as the test student. The score for the dropped assignment is subtly lighter (screen shot below). Finding the dropped assignments might be easier for students if they arrange their grades by Assignment Group rather than Due Date.