No uniform grading system exists for primary and secondary schools in the United States, although many primary schools use a letter grade system and many secondary schools use a grade point system. Typical letter grade systems run from "A" as the best grade to "F" as the worst grade.
Most letter grade systems include plus and minus variations on the letters and skip the letter "E." Typically an "A" is awarded when a student receives 90 percent or more of the possible points, with other letter grades corresponding to declining 10 percent intervals.
Grade point systems typically operate on a 4.0 or 5.0 grade scale, where this number constitutes the highest possible grade. Many grade point systems still assign letter grades but convert them to the number scale. For example, a B becomes a 3.0 or 4.0. Generally minus and plus grades subtract or add 0.3 to a grade. Thus an A- is a 3.7 or 4.7 and a C+ is a 2.3 or 3.3.
In some school districts the lower primary school years, typically kindergarten through second grade, receive only pass/fail or satisfactory/unsatisfactory grades. Some grade systems of this type include an intermediate grade, such as "progressing."