 These assignments will now make up 70% of a student's grade, and students who want to boost their scores can take them again. The remaining 30% of a student's grade is made up of formative assessments or smaller assignments like homework and quizzes. A D- letter grade is also being introduced, and the grading scale will shift slightly for grades D through F. The school system says the goal was to increase consistency and clarity in grading policies. Acacia James, WTOP News.