Eight-year-old Tamika Gore stretched out her hands, wiggled her fingers and launched into a sign-language version of the nursery rhyme "Hickory, Dickory Dock," whispering the words to herself.

"That's very good," said teacher Alida Hager-Matthews, "now, everybody."

Seventeen pairs of 7- and 8-year-old fingers filled the classroom in the basement of the Academic Enrichment Center with a visual forest of "Hickory, Dickory Dock."

The center, at 6l19 Georgia Ave. NW, is a private day school directed by Lillette Green, who began it as an after-school center in 1977 in a storefront.

In seven years, it has grown into a facility for children who are in classes up to third grade. The curriculum ranges from the basics of reading and writing to Spanish, world events, black history and sign language.

"We are not a day care center," emphasized Green, sitting in her crowded office that once was a display window for new and used televisions.

"We are an educational-enrichment center," she said.

"Children are like sponges," she continued in the soft, calm tones of a seasoned teacher. "They can do so much more than adults give them credit for."

At the school, 2-year-olds are expected to master counting, the alphabet by rote and colors. Three- and 4-year-olds learn reasoning and problem solving.

As for the older children, kindergarteners learn American Sign Language, first-graders have dictionary study, second-graders learn proofreading and third-graders the geometry of solid figures, and everyone gets a weekly black-history lesson.

Along with the emphasis on education, the center's other key to success is in providing extracurricular experiences.

"We do things that parents can't because they are very busy," said Green. "We take our kids to museums, concerts, parks, nature walks; the whole key is exposure."

"I think the reason black kids don't do as well as others on standardized tests is because they are not exposed to as much," continued Green.

"But our kids are, and it shows up on the tests they are given," she said. They scored very high and they all read two and three grades above level."

The school, nestled between the Golden Touch Beauty Salon and the Holy Mystery Mountain Church, is filled with the offspring of middle-class families in which the mother and father work as dentists, lawyers, mechanical engineers, teachers, police officers, electricians and carpenters.

These parents, most of whom live in the city, have been attracted by the school's accelerated curriculum, which nudges the kids towards achievement levels that their parents demand, and by the school's long hours, 7:30 a.m. to 6:30 p.m.

Green opened her center as an after-school facility with 30 children in a borrowed classroom; it expanded to become the Academic Enrichment Center in 1979, and is now housed in a former martial arts studio and radio-television store.

It is a year-round facility serving more than 100 youngsters aged 2 to 8.

"I had just finished graduate school and was ready to begin my teaching career," said Green, a single parent, who has a 12-year-old daughter. "But I thought, what am I going to do in the afternoons with my daughter, who had just started preschool."

Green's mother, Ruth Shirley, one of the center's nine teachers, added, "When we first saw this place, it looked so large, I thought, what are we going to do with all of this space? Now we barely have enough space."

Each grade has its own work area, divided from the others by a hodgepodge of desks, bookcases and storage cabinets, and each is colorfully decorated with crayon drawings, cutouts and black-history posters.

In the basement is a fully equipped kitchen used by the nutritionist to prepare breakfast, lunch and afternoon snacks for pupils and faculty.

"The 2, 3 and 4-year-olds are afforded the opportunity to take naps," laughed Green, "but they don't always." According to Gregory Gillette, whose 5-year-old daughter, Erica, has attended the center for three years, one of the school's major attractions is its low pupil-teacher ratio.

"They have a less than 15-to-1 ratio 15 children to every teacher ; the children receive a lot of attention," said Gillette, a mechanical engineer. "Erica has a real positive attitude towards going to school every day."

The center is self-supporting. Tuition is $210 a month for the preschool and $240 a month for kindergarten through third grade.

The school's active parent support group raises money for extras, such as the school's playground that is filled with the latest equipment, erected by volunteer carpenters -- the pupil's fathers.

The center has an after-school program for about 25 youngsters in the first through sixth grades, some of whom are picked up by the center's vans from nearby schools such as Brightwood, Takoma and Shepherd. Until they are picked up by their parents, the pupils work on their homework and have a supervised study and play period.

"I built this place from plywood and milk grates," reminisced Green as she wallked through the crowded learning area. "And I fix everything with duct tape. But our kids do so well when they have to enter other schools after our third grade. Love and attention is so important, and they get plenty of that here."