Susan V. Mills, Prince George's County school board member, peeked over her husband's shoulder as he tugged at the lever of a one-armed bandit.

Click-click-click, the lemons, oranges, and bells whirled around. The Millses watched intently, then shrugged when they came up empty handed. Casually they walked past the crowded gambling tables of the MGM Grand Hotel, Mrs. Mills in her sparkling jewelry, platinum blonde bouffant hair style, and crushed velvet evening outfit blending in easily with the eager evening betters.

Across the street at Caesar's Palace, where the Pointer Sisters and Andy Williams were about to begin their evening show, board dmember Susan B. Bieniasz cradled her cocktail and explained how school board chairman Jesse J. Warr Jr., had taught her how to play the dice tables.

A little earlier that evening at the Las Vegas Convention Center, Montgomery County School Superintendent Charles M. Bernardo sat tapping his toes in time to the singing of Dionne Warwicke as she glided through a medley of her old songs.

"That's a song she did with Burt Bacharach," he whispered knowledgeably as he patted his knee.

Some sort of secret rendezvous of area school officials for a weekend of fun? Wrong. Bernardo, Mils, and Bieniasz were just several of more than 17,000 other school administrators from around the country who had flown up to 3,000 miles to discuss education in this city of slots, barechested show-girls, and glittering casinos, largely at tax-players' expense.

It was the 109th annual convention of the American Association of School Administrators, and there with Mills and Bieniasz were seven other Prince George's County officials, including two other board members, as well as 12 school officials from Montgomery County, two from Alexandria, one from Fairfax County, and two from the District of Columbia.

"Some people might get concerned when they hear that we attended this convention in Las Vegas, but it is a valuable educational experience," said school board chairman Warr, who stayed at the Marina Hotel where the Millses, Mrs. Bieniasz, and fellow board member Norman H. Saunders also stayed. Outside the Marina, a huge glittering sign noted that the hotel was the home of the topless "Bare Touch of Las Vegas" review.

"They really are bare," said Mrs. Bieniasz who said she peeked in at the show.

Other Prince George's County school officials who attended the conference, which was held in Las Vegas for the first time, included Edward J. Feeney, superintendent of schools; Allan I. Chotiner, deputy superintendent of schools; Dr. Lewin A. Wheat, assistant supertendent; Paul M. Nussbaum, the school board attorney, and the school's public relations director, John R. Aubuchon.

Asked why Aubuchon was flown at taxpayer's expense to Las Vegas and housed in the famous and luxurious Sands Hotel, Bieniasz shook her head and said, "I really can't tell you why he's here."

Board chairman Warr chuckled as he explained, "Oh, John is probably coming to the convention to add his public relations perspective to it."

Aubuchon, a former television reporter for WTOP, said he was attending the convention because "it is good for me. It is providing me with a broad range educational perspective.

"There is a certain amount of camaraderie I will have a good time at nights, but I am also here to learn," he said.

The public relations director, who attended seminars and strolled through the exhibition area picking up samples of handouts, said he would see Paul Anks and Hellelujah Hollywood at the MGM Grand Hotel, Bill Cosby and The Silvers at the Las Vegas Hilton, as well as George Burns and Dionne Warwicke at the convention center.

As for the cost of Aubuchon's trip, he conceded that it exceeds the $225 authorized for his out-of-town travel. He and his wife - whose trip he paid for - both flew to Las Vegas and both stayed in the Sands.

When asked how he would make up the excess travel expenses, Aubuchon said, "I will transfer funds from another account where I can save some money. For example," he said, "the $100 budgeted for photo supplies in my department - I'm not going to need all of that money this year. There should be some money left over."

It was a method of obtaining additional funds for travel that apparently has not been cleared through the superintendent.

"There will be no transfer of funds," said Feeney, who added that Aubuchon would have to pay all travel expenses above $125 out of his own pocket. "I'm not signing any transfer of funds. It would not be fair to others."

Although costs for this convention were higher than for other conventions and pleasure was closer at hand, most county board members and administrators seemed to be regularly attending seminars and exploring the convention exhibit areas.

"This is one of the few places that board members and administrators can sit down and informally discuss problems and develop strategies," said Mrs. Bieniasz . Formal situations often hamper free exchange of ideas, she said.

A board member from Montgomery County, Mrs. Verna M. Fletcher, said she was totally against spending Public funds to attend out of town conventions until a co-board member convinced her that she could gain valuable experience.

"I did not believe in spending public money like this, but board member (Roscoe R.) Nix told me it was a good idea to get out and talk to educators across the country.

"Who are we in Montgomery County to say we have the money and best education systems and don't need to listen to others?" she asked.

During a conversation at the small Montgomery County party at the Las Vegas Villa Roma Motel where most of the Montgomery County board members stayed, Mrs. Fletcher said she had gained valuable insight from other educators across the country.

The cost to the taxpayers of the trip to Las Vegas could run more than $500 per person, a figure based on known air transportation, hotel, meal, and ground transportation costs. Exact figures were not available.

In any event, there is certainly enough school funds being held in reserve for just such a need in Prince George's. There, school officials this year set aside $12,000 in total travel money for the nine school board members, as well as $3,000 per board member in personal expense money.

It is not clear how much of the typical $17.50 dinner show meal charge - which includes entertainment by top performers - will be covered by the expense money.

In the exhibition aisles of the convention, which ends Monday, vendors, jugglers, and magicians attempting to sell educational books and materials to school boards, handed out leaflets and gimmicks ranging from metric conversion tables to Frisbees.

Several board members including Warr, Bieniasz and Saunders were stopped by one vendor who said: "Take this free poster of Jimmy Carter. It glows in the dark and he isn't smiling."

A few yards away the trio of board members stopped to picked up free Frisbees and then farther down the convention floor the group stopped to discuss a possible use of new reading and writing materials and briefly evaluated the possibilities of using a new information retrieval system for student records to supplement the unit they now have in operation.

While seminars seem to fascinate new board member Bieniasz and the shows delighted her, she said she did not enjoy gambling. "You know gambling isn't really that much of a challenge to me.

"The only gamble I really had fun at was when I decided to run for the school board," she said.