Shades of Buck Rogers. Without teachers, grades or penalties, but with the aid of futuristic electronic teaching machines, learning can be fun and painless. Elementary reading and math, shorthand, touch-typing, speed-reading, algebra, geometry and a college SAT review course said to raise scores 100 points are among the twenty-three courses given at Leisure Learning Center, a store which sells education. Each course takes place between you and a computerized machine that askes questions in living color and sound and never loses its temper. When you push the wrong anwser button, it never says, "I told you that last week, dummy." It merely repeats that question again and again until you get it right. Costs range from $39 for a self-paced art appreciation course development by the National Gallery of Art's extension service to $99 for two thirty-lesson educational enrichment courses - alphabet and phonics for the 3- to 7-year-old set, reading, math and French for 5- to 11-year-olds. For those who like their cerebral calisthenics even less structured, Leisure Learning Center is also stocked with learning games. Brainy Blocks, Polydoodles and Wee Shapes teach geometric and logic fundamentals to small ones. Logicom, a strategy game, and Magnetic Math, designed to improve basic math skills, are for older mental gymnasts. Prices range from $3.95 to $6.95, proving that one of the best buys on today's market is knowledge.

Leisure Learning Center, Beltway Plaza Mall, 6098 Greenbelt Rd., Greenbelt. Monday to Saturday 10 a.m. to 9 p.m. 474-1200.

DEBRA STARR