Aaron Gilbert worked hard at math and science and made good grades as a junior at Poolesville High School. Still, the idea of using those skills in the workplace was a bit unimaginable.

The unimaginable became the possible last summer after Aaron attended Hopkins Engineering Advanced Summer University Program (HeadsUp), sponsored by Johns Hopkins University's Montgomery County campus. Aaron, 16, got a better understanding of what engineering is and how to pursue a career in the field after college.

"It was a really good experience that showed me how you actually use engineering every day," said Aaron, who plans to major in computer, biomedical or electrical engineering.

HeadsUp is designed to get more high school students and college freshmen interested in engineering. Last week, Hopkins held its fourth annual recruitment fair at its Rockville campus to get students to sign up for the program.

"A lot of students we find are good at math and science, but they often don't know what they can do with those skills," said Richard Scott, director of HeadsUp. "Everything we deal with in life is really about engineering. We show them there's a whole, wonderful, wide range of fields available to them."

HeadsUp students attend a college-level class in the summer twice a week at the Rockville campus. Some of the students are then chosen for internships at biotech, engineering and science-related companies in the region, including Montgomery County. Students receive three college credits for the classes, and some of the internships are paid.

"You go to class 2 1/2 hours a week, and the rest of the time you're on the job learning," Scott said.

The classes focus on such concentrations as electrical, computer and environmental engineering. In a basic class on what engineering is, students design and build a model bridge.

To qualify, a student must have completed the sophomore year of high school and have at least a 3.0 grade-point average. Each class costs $1,530, and financial aid is available.

Hopkins said 22 students from the Washington region took its classes last summer and were placed in internships at 14 engineering and science companies throughout the region. They include Quanta Systems, a federal security contractor in Gaithersburg; Bechtel Corp., an engineering and construction company in Frederick; and Virion Systems, a biotech company based in Rockville.

Scott said part of the recruitment fair is designed to attract companies that are willing to hire the young workers. Some executives are reluctant initially to hire the students but find that once on board, the students have a lot of energy and ideas to contribute.

"We do have to sell it to companies," Scott said. "They get the area's best students to infuse curiosity and life and excitement into their company."

One HeadsUp alumnus who is now a senior at Wootton High School in Rockville made Web pages for ITA Corp., a software developer in Rockville, as an intern and then continued to work there during this school year.

Some company executives said they plan to follow students who have interned for them through their college studies and possibly hire them after they graduate.

Phil Blackman, president of Quanta Systems, has hired interns since HeadsUp started.

"It gives an opportunity for the best and brightest minds to get ahead," Blackman said. "It gives them a chance to really get their heads into engineering. Some of them are so intellectually mature that they're not really getting challenged enough in their high schools, and at companies they can see what they know."

Aaron Gilbert worked for a defense contractor at the Pentagon last summer.

"I did installation of computer cables for the Joint Chiefs of Staff," Aaron said. He plans to return to the job this summer.

Dominick Memoli, 16, of Olney also had a paid internship last summer at the Pentagon; he and Aaron had to get security clearances, Scott said.

Dominick, a junior at St. John's College High School in Washington, said he learned a lot more about engineering after being in HeadsUp.

"It's a field that I'm now starting to look into as a career," he said. "I really didn't have an idea of what it was about."

His mother, Ann, said she has enjoyed seeing Dominick acquire life skills, such as riding the bus and the subway to his job.

"He was running with the big boys now in his class at Hopkins and working at the Pentagon," she said. "It sure beat flipping burgers. He's never going to go back to that."

The dean of the Whiting School of Engineering at Johns Hopkins University in Baltimore, Ilene Busch-Vishniac, developed HeadsUp for the Montgomery campus, Scott said. There is a well-established summer program at the university's Baltimore campus, where high school students take courses during the summer and stay on campus, but there is nothing like it elsewhere. HeadsUp was developed with the help of Sarah Steinberg, executive director of the part-time Hopkins engineering program in Rockville.

"This brings the opportunity to Montgomery County," said Scott, who is also the director of the part-time engineering program for Hopkins in Rockville.

Administrators said they wanted to encourage students to become engineers as baby boomers retire in increasing numbers over the next two decades.

"A lot of upper-management jobs in engineering will be open," Scott said. "These young engineers we're training will get pushed into those companies and into those positions."

Marvin Perlman, above left, an electrical engineer with Shapiro and Duncan Inc. of Rockville, watches Shankar Mohan Kumar, 11, his father, Sundaramoorthy, and sister Suganya, 15, work on an electrical problem at a recruitment fair last week for Johns Hopkins University's HeadsUp program. At left, Gavin Kanga, a returning student to the fair from Wootton High School, works on a robot.