The weighty issues addressed yesterday on the Mall could have come from a public policy think tank -- bringing troops home, lowering gas prices, ending poverty.

But the messages were on notebook paper, decorated with flags and hearts and represented the thoughts of 4,000 third- and fourth-graders from across the country. The letters, displayed side by side yesterday on a light blue, plastic scroll, stretched from Seventh to 14th streets NW.

The students wrote of their hopes for a world without war, pollution or hunger. They wrote of helping the homeless and growing up to be doctors, football players and veterinarians.

The project was sponsored by Pilot Pen Corp. of America and designed to show children that "there really is power in the written word," said Ronald Shaw, the company's chief executive.

"This is to let them know that you really can write a letter to a high government official and get a response," he said. President Bush "may never, ever see those letters, but these kids are hopefully going to receive a reply in an envelope addressed to them from the White House."

Based on the litany of requests, however, it is clear that the children want more than a response. They want change.

Thaddeus Cradle of Cleveland Elementary School in Northwest Washington asked for a recreation center where "people will help you with your homework." Kevin Flagg, a student at St. Matthias Apostle elementary school in Lanham, asked, "If we lose the war on terror what will happen to us?"

Alvin Nixon, a tourist from Canada visiting the Mall yesterday, noted how candid some of the letters were. "It's nice to see that American children are being encouraged to have a voice," said Nixon, 51.

While most letters dealt with pressing national issues, some children just wanted to let the president to know how much they like pizza and hamburgers. Others addressed Bush as if he were Santa Claus.

Antione Harvest, also of Cleveland Elementary, wanted a mini-motorcycle. And Gabriele Noble, of Watkins Mill Elementary in Montgomery Village, asked why you had to be a certain height to go on a roller coaster.

Ashley White of Falling Creek Elementary School in Richmond wrote her prescient letter in January. "How," she asked, "can scientists help prepare us for natural disasters?"

Ryan Thorpe wrote about violence. "I think you should stop making guns, they start even more trouble."

His message will be among the letters when they are bound and delivered to Bush in a few weeks.

"By writing a letter, I learned that you can change stuff," said Ryan, a fifth-grader at Cleveland Elementary. "I think he will do what I wrote and asked."

A letter addressed to the president from Tuscaloosa, Ala., speaks of preventing drug use and the need for medicine for the ill. Letters from elementary school students nationwide stretch from Seventh to 14th streets NW. They will be bound and delivered.