A standard score of 100 on a standardized test of math or reading would also be average. As a standard score gives a position in relationship to a reference group, the score by itself is meaningless without knowing the position of the student when compared to all students who took the same test. A standard score of 90, the beginning of the average range, corresponds to a percentile rank of 25. A standard score of 110, the uppermost end of average, has a percentile range of 75. So a child at the 30 th percentile on a test of reading or math is performing within the region of what would be considered “average.”