ELEANOR JOHNSON is an 85-year-old retired schoolteacher who lives in Frederick, Md., and if you are under 60 she very likely influenced your childhood.

Because 50 years ago last month she started a little newspaper called My Weekly Reader, which someone figured out has been read by 400 million children and which now has a circulation of 7 million, well above Time or Newsweek.

(Influence indeed. When I was in the sixth grade at the Utica County Day School, known locally as the Utica Cat and Dog School, we studied Hitler and Mussolini in our Weekly Readers - it being 1937 - and we decided to have a class dictator instead of a president. The school being what they used to call progressive, Miss Lamont said fine. It worked beautifully. Everyone wanted to be dictator, so every week Miss Lamont had the current Fuehrer step down and appoint a successor. It was only much later that we figured out that the actual dictator was Miss Lamont herself).

"I was assistant superintendent of schools in York, Pa, in 1928," said Johnson, who gets up at 4:30 a.m. to work on the paper when she's not commuting to Middletown, Conn, where the Reader is published by Xerox.

I was especially interested in reading, and I had done some research in it at the University of Chicago, and I saw that children were being given a lot of myths and folklore to read but were utterly illiterate about what was happening in the world. The idea simmered for a year, and then I ran into a publisher in New York."

The publisher was William C. Blakery of the American Education Press in Columbus, Ohio, and he was not one for letting ideas simmer. He wired her at the university: "Save Sunday ready to start your children's newspaper."

"So on a blistering Sunday in August, we met in the Blackstone Hotel in Chicago and on the same day we mapped out policy and framework and format. A month later he started putting it out."

At first Johnson was too busy to edit it herself but trained others to do the job. She had already written a series of readers and a pioneering work book. For several years she would pick up the editor at the train station in York on Saturday mornings, work all weekend with her and put her on the train back to Columbus Sunday night. By 1935 she was working full time for Blakey.

"I guess you want to know why we succeeded," she chirped during a pause. "The first thing was our policy to present selected news of value and interest to children with accuracy and fairness, colorful but uncolored.We've lived up to that for 50 years, and that't not easy, brother. Also, we gave teachers material they couldn't get elsewhere at at lower cost."

The paper today costs $1.15 for 28 issues, comes in seven editions for the seven primary grades, is paid for mostly by school boards, though four out of 10 papers are still bought by the children directly through their teachers. Weekly Reader (it dropped the "My" some years ago) also goes to teachers of English in 66 countries.

The first issue was four pages and featured matching articles about Herbert Hoover and Al Smith, the Presidential candidates of 1928. The headlines were "A Quaker Boy" and "A Little Newsboy." There was also a letter from Uncle Ben ("Uncle Ben loves children. He spends all his time traveling, so he will have interesting stories to tell them. He has an airplane all his own. He hops over mountains, across seas and knows little folks all over the world.") who described flying in a German glider. On the back page were a quiz, a project and some information about dandelions.

"Dig up a dandelion plant, root and all. In the space above, finish the drawing with crayons. . . "

Today, the paper has color photos and is slightly larger, running is many as 12 pages for the senior version. The different issues have names: News Patrol, News Parade, Eye, Surprise, Buddy's Weekly Reader and so on. For the very young there are plenty of cartoon figures from the 10 staff artists and, for the main news event, a fine photo of a workman cleaning one of the faces on Mount Rushmore. What would children's newspapers do without Mount Rushmore?

The senior edition headlines a locust plague in Africa and Asia and features stories about the tax revolt, the snail darter, the "Longest Walk," the Pompeii exhibit, a behind-scenes look at the technology involved in making "Battlestar Galactica" and a quick profile of baseball slugger Rod Carew.

There is also a self-help column, "Controlling Your Temper," and a quiz page with a crossword puzzle.

"The editors always want to include adult subjects that are over the children's heads," said Johnson. "We fight 'em. Like cloning. Now, we would just confuse them with that. We try to keep away from TV stuff. We stick to the news. That's our business. We're not a magazine, not a game book, not a work book."

Still, Weekly Reader sends a Teacher's Edition along with each issue giving tips for teachers ("To stimulate discussion about the story, ask, "Why would it be less difficult to stop an insect plague in the U.S. than in an underdeveloped country?") and promoting Weekly Reader Skills Books, which for 65 cents help improve map-reading ability, graph comprehension, use of the library or dictionary.

Terry Borton, the editorial director, agrees that it's hard to decide what news to include.

"We know they watch TV, of course, we assume they average six hours a day. But we don't assume that they know the news. Take the Middle East talks. They knew something was going on, but they didn't know what the issues were. They see that President Carter is at Camp David, and the reaction is, oh, the president is off at camp, huh?"

There is controversy, of course. The paper deals with the tax rebellion in its more advanced editions, and there was a special issue at the time of Martin Luther King's death. But nothing about the Son of Sam.

"When I started to work here a year ago. I went back to the archives and looked at the issues I read when I was a kid, and I found I learned a lot of important stuff from the Reader," Borton said.

Though the four-week lead time keeps the paper somewhat behind on the latest sensation, its 26 editiors stay in touch by reading the major news publications and listening to reports from teachers in the field. Nearly all the editors are veteran teachers themselves and are familiar with the tricky problem of writing clearly for the young. reducing an event to say, a 200-word item for second-graders.

"We're very careful to keep out political bias." Borton said. "But we cover the important stories."

It goes both ways, too. Readers are polled regularly on the issues of the day, notably the presidential campaigns. Since 1956, the children have predicted correctly the winner of every presidential race except the one in '63 when they voted for Robert Kennedy before his assassination.