Teachers at a job fair in Downey show the bright side of their careers to some students who might decide someday to be teachers.

A small group of teen-agers stood in front of Nicholas Perikli, mesmerized as he brought to life the basics of the United States Constitution.

“Just remember this--Let’s Enjoy Jokes Right After School Recess,” Perikli told the youths. The phrase, he explained, might help them remember the issues behind the seven articles that compose the document-- l egislative, e xecutive and j udicial powers, r elations between the states, a mending the Constitution, s upremacy of the federal government and r atification.

Perikli, a government teacher at Mayfair High School in Lakewood, delivered the lesson last month as he and about 50 colleagues from throughout Los Angeles County took part in a job fair at Apollo Community Center in Downey. The program, attended by more than 500 high school students who professed an interest in teaching, was sponsored by the county’s Office of Education.

“There is going to be a need for 20,000 to 25,000 new teachers in Los Angeles County alone by the 1990s,” said Terry McAlpine, one of the event’s organizers. She said the goal of the job fair was to “enhance the image of teaching” by showing the students how captivating it can be.

Many students think of a typical teacher as “a woman with her hair up in a bun with glasses who is mean” and who is not paid very well, said Lakewood High School student John Wilmarth, a junior.

But at a booth near Perikli, Gale Odell, a vice principal in Long Beach, and her husband, William, basketball coach and boys athletic director at Millikan High School, were trying to dispel the notion that teachers are boring, unattractive and poor.

“Between the two of us, we make over $80,000 a year,” Gale Odell said. “We go to parties. We go to church. We have fun just like anybody else.”

Nobody at the fair accused Perikli of being a bore. “He’s quite the showman,” one teacher said in awe.

Raul Lopez and Jose Olivares were still talking about Perikli 30 minutes after meeting him. The sophomores at Jefferson High in Los Angeles said they would learn more if all teachers had Perikli’s enthusiasm.

“He has a very interesting way of teaching,” Lopez said. “He seems a little bit old, but he is so energetic . . . I wouldn’t ditch his class.”

Both were amazed at Perikli’s memorization tricks.

“If you studied it just a little bit, you could do it from memory,” Olivares said.

“We didn’t even know we were learning,” Lopez agreed.

It was an educator like Perikli who got Richard Arthur interested in becoming a teacher more than 30 years ago. But Arthur, who teaches history at Jefferson, believes that it is the system that makes men like Perikli unique.

“If you can keep your class quiet, they’ll like you even if nobody is learning,” Arthur said. “They’ll make you a principal.” But if your class is “loud and arguing but learning,” administrators will knock you down , he said.

Perikli, a fireplug of a man who makes sharp, pointing motions with his hands as he lectures, said teaching is “an attitude.”

“Through experience, I have learned certain strategies,” Perikli said, explaining his use of mnemonic devices to help students memorize. He said that by using these tricks, he is able to give teen-agers a sense of accomplishment they might have been lacking.

“All of these youngsters come to you at different levels of readiness, and it’s important that you gear your whole presentation to making sure that everybody learns as much as is possible,” Perikli said.

But no matter the extent of a teacher’s preparation, no matter the knowledge he possesses about his subject, failure is assured if one key element is missing, Perikli said. “The whole (classroom) presentation must project a feeling that ‘I like being here.’ ”