When students view the gradebook, a question I often get asked as a teacher is "What can I do to raise my grade?" This question can usually be broken down into the following questions.
Teachers should not be the sole guardian or lone answerer of these questions. Students should be able to enter "What If" mode and change or enter grades that they currently have in the gradebook. In "What If" mode the student can then see in real time the impact on their grade: if they change in a grade, or add a grade that was missing.
NOTE: this is especially useful for standard-based-grading gradebook, since the weights of non-assessments is considerably less than that of assessments.
Empower students to manage their performance. Call your IT people, tell your PowerSchool administrators, alert the media, call your congress-people: implement "What If" feature today!