In special education, average test scores are particularly useful in standardized evaluations and in tests designed by teachers. Educators determine the average by adding a set of numbers and dividing the sum by the total number of numerals used in calculating that sum. Anyone who’s been graded on a curve likely knows the concept well. Teachers and specialists can use averages to determine the “middle” group of test-takers.

Statistically, about 68 percent of any large group of students will score within the low average to high average range on most tests.

(The other 42 percent will be in either the above average or below average group.) The exact average score itself defines the 50th percentile.