The most common grading scale in public schools is a 10-point scale. Letter grades (typically A, B, C, D and F) are awarded based on the student’s numerical grade.
In a 10-point scale system, a numerical score of 90 percent to 100 percent receives an A, 80 percent to 89 percent receives a B, 70 percent to 79 percent is a C, 60 percent to 69 percent is a D, and 0 percent to 59 percent means a failing F.
A common variation is the addition of “+” and “-“ to the letter score, which denotes a more specific numerical grade. For example, a B+ represents a grade of 87 percent to 89 percent, a B is 83 percent to 86 percent, and a B- is 80 percent to 82 percent.