Phillip Norton, an eighth grader from McLean, usually plays basketball Saturday mornings. Sarah Lester, 12, normally rises to her toes at the Washington School of Ballet. Kelly Galvin, an eighth grader at Marymount Junior School in Arlington, likes to sleep late and watch the "Smurfs" cartoon show.

For the last seven weeks, however, these youngsters and a dozen other students have forgone their usual Saturday morning pastimes to review fractions and percentiles, semicolons and gerunds.

In what is perhaps the youngest twist to the entrance exam preparation game, the 15 students are drilling for the Secondary Scholastic Aptitude Test (SSAT) -- the national admission test for most prestigious private secondary and junior high schools.

"I am distressed in some ways that we need to offer the SSAT course, but it's something that parents have demanded," says Sue Gurland, of Traveling Tutors, Inc., one of a small number of Washington area testing services that offers preparatory study for the SSAT . . . About 50 students, from sixth graders to ninth graders, are enrolled in similar courses in the area.

Demand for test courses at an early age results from the same type of pressure to succeed that is typical of the college entrance preparation course, says Gurland, and is, in some cases, more amplified. Parents view admission to a good secondary school or junior high school, which can have five times as many applicants as openings, as the first step to acceptance at a prestigious college.

"I really don't want to go to a public high school," says Norton, a student at the private Langley School. "I want to go to a good school so I can get into the college of my choice."

Norton has set his sights on the University of North Carolina.

"Some of my aunts and uncles went there and they have a good basketball team," he explains. "A really good one."