David Meyer brought Wolverine, his gerbil, to be the motor in a generator experiment. Traci Greer talked about "Bovine Mastitis, a $2 Billion-a-Year Problem." Abigail Davis demonstrated a talking robot with a Spanish accent.

So it went last week at the second annual science fair at Takoma Park's Piney Branch Elementary School, the only school in Montgomery County specializing in mathematics and science classes.

For a day and a half, Piney Branch's 117 fourth, fifth, and sixth graders displayed the results of their scientific experimentation. Unlike other elementary students in the county, Piney Branch students have a science class every day and a laboratory session every week.

After four slow, start-up years for the science program, school officials say, Piney Branch finally seems to have hit its stride. Test scores have jumped, student transfers into the school have increased, the "gifted and talented" classes have expanded and a new computer program and laboratory have been added.

Takoma Park is part of the county's most racially and economically diverse area. Piney Branch, which has only grades four through six, serves the area along with three other primary schools with high minority enrollment.

"Everyone in the county seems to have this 'down-county mentality' that schools in this area are terrible," said Denise Knoller, director of the science fair and the school's science curriculum coordinator.

"I wouldn't want to be any where else," Knoller said. "The kids are delightful. They're curious about everything . . . and the wonderful thing about the science 'magnet' is that it's for all types of kids, not only for the very bright."

In an effort to attract more white students to schools in areas where minority enrollment was far above the county level, Montgomery County in 1976 established the so-called "magnet programs," consisting of special classes not offered elsewhere, in seven schools in Takoma Park and Silver Spring. Seven years later, Piney Branch is being looked at by school officials interested in setting up similar programs elsewhere to facilitate school integration.

Earlier this month, the county school board voted to add similar mathematics and science programs at Rosemary Hills, Chevy Chase and North Chevy Chase elementary schools. These are schools that, under current integration plans, are expected to have large minority enrollments. The board hopes that the programs will help draw additional students from outside the schools' assignment boundaries.

"Any way you go, the programs generally are going to have to be the same," said Judy Patton, the school system's director of quality integrated education, who administers the magnet programs. "But what we need to do is to get more information about the programs out to the public. We need to do more advertising if we are going to reach our goals."

After the special academic programs were established in 1976, few students were recruited and parents were given little information about the programs. By 1981, only a third of the number of students that the programs had been expected to attract had transferred to the seven schools. As a consequence, a highly critical school system report noted, the integration goals of the magnet programs were "probably doomed" from the start.

Until two years ago, only one student had transferred to Piney Branch to take advantage of its science classes. But today, school officials say, that has changed. Minority enrollment is still high, totaling 63 percent in an area where the 40 1/2 percent minority population includes Hispanics, blacks and Asians, and a small number of students continue to transfer out of the school.

At the same time, however, students from outside the school's five-square-mile district, which includes most of Takoma Park and east Silver Spring, also are enrolling, officials said.

Between March 1982 and last January, 20 students transferred into the 117-pupil school, Patton said. The year before that, there were eight.

If the trend continues, school officials say, they expect the minority-white enrollment to begin equalizing.

"We have got a lot of unique programs that people are only now beginning to hear about," Hatchel said. He cited these special features of Piney Branch:

* It is the only elementary school in the county with a science coordinator and science laboratory.

* It has one of the few teachers hired solely to instruct about computers.

* It has a computer laboratory.

* It has six sections of gifted and talented programs.

Unlike most elementary schools in the county, students enrolled in the gifted and talented program every day attend special classes, such as social studies and accelerated science. In addition, all of Piney Branch's students have science class every day. In the rest of the county, the number of science classes offered each week in the schools varies.

Teachers in Piney Branch science classes do not use a standard textbook. Instead, the curriculum evolves around experiments and laboratory work.

"Teaching science at the elementary level is very difficult. During college, elementary school teachers do not receive a lot of science training and its hard to keep up with the advanced technology," said John Pancella, director of secondary science for the county school system.

"With a separate science coordinator, Piney Branch is able to offer a much more enriched science program and a lot more lab work. The coordinator also knows what's needed for experiments and is able to organize the buying of supplies."

"Kids love it," Pancella continued. "And the great thing is that the kind of enthusiasm kids have for the sort of hands-on activity they do at Piney Branch can't help but affect students' work in other areas."

Test scores at Piney Branch tend to bear out Pancella's observations. Students in the fifth grade scored in the 64th percentile on the California Achievement Test taken in fall 1980. Although still slightly lower than the countywide average, fifth graders this year scored in the 74th percentile. In addition, 46 percent of the students scored in the top quarter nationally.

"We've got all levels of kids here, from the very top to the very bottom," Knoller said. "But one of the things I like best is seeing the kids who have had really major problems in school suddenly get excited about a science experiment.

"I have two kids, fifth graders, who never followed through on anything, but then they got interested in their project with the gerbils and the rats and the mice. I've never seen them motivated so continuously. They read all sorts of books and did all kinds of research. It was truly terrific."

One parent observed that in addition to the academic program, one of the biggest advantages of the school is its diversified student body.

"Carlota likes the program very much, but she has also made friends with all kinds of kids," said David Bernal, a Labor Department lawyer, of his daughter, who is in fifth grade. "We think that has been an important part of her education, and it is the reason we like the school and are comfortable living in this area."

Interviewed at the science fair last week, David Meyer, 12, said that the school is "really neat." A walking encylopedia of generator terminology, he was nonplussed when his gerbil, Wolverine, had to be sent away in disgrace from the experiment after biting a boy at the next table.

David began spinning the wooden wheel that had been Wolverine's assignment as he talked of voltmeters and armatures, which he said "sort of turns around and breaks the magnetic field." He also began punching out programs on the computers that had been set up to monitor the experiment.

"I just really like it. I pretty much started with computers in third grade when I came here on a tour. Then, in fourth grade, I got to use them," said Meyer, whose father is a scientist with the Nuclear Regulatory Commission and whose mother has a master's degree in mathematics.

"But what I really like is generators, because you're sort of creating energy. . . . Don't you think its neat?"