AT THE GRADUATE level, American education in science and mathematics continues to be the best in the world. The trouble lies at the lower levels and raises concern that even the best graduate schools may not be able to produce enough trained Americans to adequately replace the present generation as it moves toward retirement. The graduate schools are educating huge numbers of foreign students, a noble enterprise and a great contribution to the scientific advancement of the rest of the world. But some of those foreign students have been admitted because the universities can't find as many qualified Americans as they would like.

Starting a scientist's education in the undergraduate years, or even in high school, isn't good enough. It needs to begin much earlier, if children are to acquire a strong sense of numbers and the logic that lies behind them. It's not just a matter of recruiting professional scientists. In a country that owes its living and its manner of life to advanced technology, it's unhealthy to let society split into a highly sophisticated priesthood that understands it and, on the other side of an invisible boundary, a scientifically illiterate majority -- a sort of intellectual proletariat -- that simply doesn't get any of it.

A number of scientists and their professional organizations are beginning to devote serious attention to the state of scientific education in this country. For sheer courage and energy, Leon Lederman's campaign to bring real science into the Chicago public schools deserves special attention. He intends to start in the elementary schools, persuading kids that there's more to math than arithmetic drills. Mr. Lederman, one of the country's outstanding physicists, now at the University of Chicago, is undertaking a public service of enormous importance.

He plans to begin by teaching teachers. He is organizing a new academy for math and science teachers, where they will learn to draw kids more deeply into the subject with simple apparatus and rudimentary materials. The central idea is to get the children to take an active part. Most of science is, after all, tinkering and messing around. That's why people who try to learn science solely from books never quite capture the spirit of the endeavor.

It won't be inexpensive. But in a school system with a 40 percent dropout rate, Mr. Lederman's experiment may well prove considerably less expensive than continuing to tolerate the present rate of failure.