You'll have to forgive Rudolph Hines if he was not especially impressed when President Reagan called Martin Luther King Elementary School in Southeast Washington yesterday.

Rudolph, a fifth grader at King, has met the president twice and corresponds with Reagan every month, receiving prompt, personal replies. Since first grade, Rudolph has been the president's pen pal, one of the perquisites the King school gets from being adopted by the White House.

"He says what he goes through as the president, like the summit with Gorbachev," Rudolph said. "I write about what I'm doing in school."

For those students whose relationship with the chief executive is a bit less cozy, yesterday's two-minute telephone call was a pretty neat way to kick off the school's celebration of Martin Luther King Day. District schools, as well as federal and most metropolitan government offices, will be closed Monday in observance of King's birthday.

"The president is calling us because we're his school," said Jannell Tilley, a fifth grader who played King in the school play.

Jannell and the rest of King's students listened to the brief conversation between Reagan and Principal William Dalton over the public address system in the auditorium.

"Today is the birthday of a great American hero," said Reagan, who had opposed a federal holiday in King's honor during his first term as president. "Dr. King was a man who dedicated his life to the pursuit of the dream that one day, all Americans would be judged not by the color of their skin, but by the content of their character."

King's image -- and his teachings -- are omnipresent at his namesake school. The students, some of whose parents are too young to remember the civil rights activist, have learned some basics of his life.

"He didn't believe in violence," Jannell said. "The whites treated the blacks wrong. So him and his people marched around the city and he made great speeches. I want to be something like him. I want to be a football player or a basketball player or a singer."

At schools all around the city yesterday, King Day assemblies featured recordings of great speeches and student skits dramatizing the famous confrontations of King's movement.

At Paul Junior High School in the Manor Park section of Northwest, Principal Thomas Collier told the students how he and King as young children "used to climb up on the streetcar and go right to the back seat. That's where we belonged at the time. It was conditioning."

The students listened closely as the principal told of playing with King as a child in Atlanta, where their fathers were ministers.

"Dr. King seems to these children like Abraham Lincoln is to me, somebody out of history," Collier said later. "We try to make him come alive for them."

Across the District at King Elementary, Rudolph Hines knew about the rule that black people had to sit in back of the bus. And he knew that King had made a difference.

"He let black people sit right in the front," Rudolph said. "If he was alive today, he probably would have helped the homeless and built more shelters."

Rudolph's letters from the president are sometimes posted for all the children to see, said principal Dalton. But a few have had to remain secrets between the fifth grader and the leader of the free world.

"Some of those letters we couldn't post," Dalton said. "The president would tell Rudolph his itinerary before it was announced to anyone."