MR. T, large-muscled star of "The A Team" and "Rocky III," passed among the multitude at 14th and Florida NW yesterday, throwing his commandments like combination punches.

"No need to be hanging around corners with winos and dopers," he jabbed, following up with, "And you have to stay in school. You can't be in the movies if you can't read."

The 350 school kids had been watching Mr. T film a few scenes for "D.C. Cab," a Universal Studios movie about zany taxi drivers, in front of the Florida Avenue Grill. They were waiting for him to come and say hello, which about 5 p.m. he did.

"Don't be cursing. Don't be giving your parents a hard time," Mr. T advised, shaking hand after hand. "I don't do any drugs, I don't smoke, and I don't hang around. And I still listen to my mother."

The purveyor of these sentiments wears a mohawk hairdo (or a Mandinka, as he calls it) and about 20 pounds of gold chains; on this occasion he also wore a set of earrings possibly made from the feathered end of bluefish lures and a wide leather belt of the sort favored by weightlifters.

When he told the children to be nice to their mothers, they paid attention.

"He's like a big brother to us," explained a Cardozo High School student, James "Mr. T" Carter. "All we have is him and Mike Warren" (of the television program "Hill Street Blues").

"He's better than Mike Warren," corrected James Smith, who goes to Garnet-Patterson Junior High. "Michael Warren plays a cop."

"I want you to stay in school for me," Mr. T called out as he moved along. "Listen to your teachers and watch out for strangers."

Nothing stranger than Mr. T, however, was seen on 14th Street yesterday. He had just finished tearing the insides out of a taxicab, and tearing a girl out of a pimpmobile a few moments earlier, and he was still in the Tarzan-like mood induced by the psychic requirements of his film persona. On the other hand, maybe he is always like that.

For all his seeming abandon, the professional Mr. T, whose name was Lawrence Tureaud before he legally changed it, did his complicated ensemble acting scene in one take, causing director Joel Schumacher ("Car Wash") to holler, "Great!"

"When are you going to give out some of your gold?" called a grown-up woman when the hero approached his gallery of admirers.

Mr. T prickled a little. "I got my gold from God," he shouted. "What's wrong is people always looking for somebody to give out gold. You've got to work hard to get gold."

A feat of strength was performed yesterday by Deborah Gadsden, a little girl, who managed to hold up Latasha Gadsden, an even smaller girl, so Latasha could get a good look at Mr. T. They were among 25 children, members of the Kingman Boys and Girls Club, brought to the film set by Jimmy Padgett, a science teacher.

"He's what we've been missing," said Padgett of Mr. T. "He projects a mean image, but for positive reasons."

"I love you, I love you, stay in school for me, don't be hanging out on the street corners," the star went along repeating. "If you hang out of the corner you'll get locked up in jail or be dead before your time."

It was a sobering message, all right, and, as Mr. T explained later, a necessary use of his power as a public figure. "I love them and I care about them and I love them," he said. Indeed, the crowd seemed to believe that, underneath the chest of a gorilla with earrings, there was a heart of gold beating for them. Several women sought to engage him in investigative colloquy.

"How old are you, Mr. T?" came a call.

"I'm 31, my birthday was Saturday, and I've got a 12-year-old daughter."

"Are you married?"

"No, I'm not."

"Do you want to get . . ."

"No, I don't."

In "D.C. Cab," some down-and-out cabbies are joined by a young fellow with ambition and are galvanized into a team that solves a kidnaping. The film will not be released until Christmas at the earliest and the ending is a secret, but there was a solid gold taxicab on location yesterday and it's a fair bet that Mr. T eventually gets the gold.

His fans liked his gold and they liked his apparent capacity for meanness, necessary because (to paraphrase the explanation of several children) the world is also mean.

However, there were not any of those Mandinka haircuts in the crowd.

Eric Andrews, a pupil at Harriet Tubman Elementary School, said he used to have one, but it "grew out." "My father cut it for me. Then my mother said it looked crazy," Eric said.

James Smith, who admires Mr. T, nevertheless disparaged the mohawk, or Mandinka, or punk cut, or whatever it is. "It's not 20th Century-Fox fashionable ," he said.

Mr. T was not close enough to hear him, and James Smith knew it.