A teacher has mistakenly added a grade to a student and wants to remove the grade, until he is ready to supply the correct grade.
When he has added a grade to a student, then it is not possible to remove the grade by choosing an empty field or press the delete button on keyboard.
How does she remove the grade from the student?
While in Gradebook click Create view -> Datasheet view and create a view. Afterwards open this view and delete the value.