Null scores, or cells which do not include a score or attempt, are calculated as a zero in Grade Center total score calculations by default. In contrast, a running total column ignores null scores within the Grade Center. This is helpful early in the semester, as it allows the points possible to adapt as students progress through assessments. However, if a student never attempts a test or submits an assignment, a zero score must be entered. Otherwise, the system will not count the missed assignment against the student's final grade.