The teen-ager's T-shirted back was bent into a C-curve. Her breath came in short gasps. Her arm pumped in sporadic bursts. BLIP! POW! WHOOT! ZAP! When it was over, she grinned. I did not grimace. My "trouble- in-River-City" attitude about video machines was beginning to thaw.

Hastening the thaw was a notion I had as she pumped a last quarter into Pac-Man: Wouldn't it be wonderful if there could be an electronic game with similar fascination that could teach kids how these computers work, so our urban kids could realize that knowledge of the same little-bitty chip that was behind the flowing and flashing psychedelic lights could mean the job that could change their lives?

Parents from middle-class homes recognize the rapidly moving technology and have the wherewithal to purchase home computers. The wealthier, in-the-know kid who becomes so fascinated with the preprogrammed synthesized voice from Berserk, for example, goes home to program his own computer. He'll have an advantage over kids from less affluent homes, unless those parents recognize that computer literacy is high-priority -- higher than those blaring stereo boxes some seem to find the money to buy. Still, that kid will remain at a disadvantage unless computer literacy becomes part of the public school systems.

In the metropolitan area, the Fairfax, Montgomery and Alexandria school systems have moved faster in introducing computers to students. The District is in the beginning stages this year and has some $2 million to put into hardware and software that school officials hope will reach about one-third of the students in the system.

The issue of equity in computer learning is concerning increasing numbers of people these days, and it is about time. A few days ago, the American Association for the Advancement of Science coordinated a conference in Washington to focus on how science and math education are keys to increasing the chances that urban kids have of getting jobs in the future. They talked of rectifying the mishmash in the education of black youth, who face a job market that increasingly is technically oriented.

They know that America is going to need urban, as well as suburban, kids because the government has determined that the skilled and professional workers must come increasingly from women and minorities in the next decades. There simply won't be enough others in the labor pool to maintain the nation's productivity without them. That is why Rep. Mervyn M. Dymally (D-Calif.) could conclude that the country's scientific and technical talent pool will need kids who at one time might have been written off.

But the kids have a responsibility, too. They must develop the mental toughness to believe they can conquer science and mathematics. It's time somebody told them that they shouldn't be scared by talk of these subjects. They aren't as hard as some people make them out to be. While these youngsters pump quarters into video games, why can't they be made to realize that as they grow to adulthood this new technology will affect the majority of jobs that will be available, and that the country is going to need them to hold those jobs?

I think the same instinctive wit and street survival skills that motivate youngsters to excel in basketball will stand them in good stead in science and math, once they make up their minds to learn it. They will play by the rules of the game and master those subjects, once they know that the bottom line will be the money to permit them to live in the manner in which they wish to live.

These urban black students face impediments: an entrenched and sometimes unfeeling public school bureaucracy, an ambition-sapping rate of unemployment, and a lack of action on technical education by the current national administration.

But these handicaps can't be an excuse for all of us not doing what we can. Parents must help their kids to meet this challenge. Why not consider buying a home computer instead of a stereo? Parents and teachers must work together and jointly use resources to make kids feel they can learn. Then the whole community must work together to assure a place for the kids once they have mastered the skills.

Those were my thoughts as the teenager smiled and the machine went BLIP! WHOOT! ZAP! That is why when the teenager grinned, I didn't grimace.