WITH THE OPENING of the school year, youngsters entering Virginia's high schools will face higher requirements for graduation. In the past, the state has required only one course in math and one in science. Entering freshmen will now take at least two of both math and science, and a third of one or the other. Maryland is contemplating a similar tightening. In the District of Columbia, all students are now required to take one year of a foreign language--a rule as unusual, by national standards, as it is beneficial.

The most interesting--and most hotly debated-- of all these changes is the Virginia State Board's decision last month to offer an advanced studies diploma for students on their way to college. It will require three years each of math, science and foreign language. Its opponents argue that this distinction among diplomas is discriminatory--that it may daunt uncertain youngsters from seeking a college education, that it stigmatizes the diplomas not designated advanced, and that it is, in the familiar term of the past decade, elitist.

It's certainly elitist. Any grading system or academic distinction is elitist. Good colleges and their admissions procedures are elitist--few less so, by tradition and practice, than the University of Virginia.

It's not the college admissions offices that need the special designation of the advanced studies diploma. The purpose of the special diploma is to focus the attention of students, and perhaps their parents as well, on the additional courses that good colleges require. College seems awfully remote to a ninth-grader. The special diploma, and its explicit demands, is a useful way to impress on young students that, for college entrance, they are going to have to do more than meet the state's minimum requirement.

The difference between the two diplomas is not so great that students who change their minds, and want to move to the more demanding program, cannot do it in the eleventh grade. Even students who graduate with the standard diplomas are not permanently shut out of college. The two-year colleges provide, among their many services, an accessible route for the late starter.

The American educational system has done a better job than any other in the world of balancing the two responsibilities of its schools: to provide the widest possible opportunities for each individual child, while advancing the most able at the speeds of which they are capable. It isn't accomplished simply by setting minimum standards for everybody. Virginia's advanced diploma will increase, not decrease, the number of children going to college, for it will provide them with an early and accurate sense of college requirements.