Okay, Ronald, you can change the number under the Golden Arches now.

Over 50 billion served.

McDonald's marked that milestone today with a gala media event here and a moment of business silence in its 8,000-plus outlets worldwide. Customers were then given a coupon for a free burger.

Just for the record, the burger designated as the 50 billionth, a Quarter-Pounder with cheese, was served at 12:24 p.m. EST to 75-year-old Dick McDonald, who with his late brother opened the first McDonald's, in San Bernardino, Calif., in 1948.

The momentous morsel was fried up by Ed Rensi, who was known as "Fast Eddie" when he started as a grillman at a McDonald's in Columbus, Ohio, and is now president of McDonald's U.S.A.

"You've got the right wrist action," McDonald said as Rensi plopped the frozen patty down on a grill specially set up in the ballroom of the Grand Hyatt Hotel, where ushers in rust-colored McDonald's uniforms directed guests and the McDonald's All-American High School Band entertained at a post-event luncheon of Quarter-Pounders and champagne.

At today's celebration, company officials recalled other moments of McHistory and replayed famous McDonald's television commercials, highlighted by the 1963 debut in a Washington ad of Ronald McDonald, alias TV weatherman Willard Scott.

The honored guests at the festivities included Art Bender, who served burger No. 1 at the San Bernardino store, and McDonald, who takes credit for designing the famed Golden Arches. McDonald and his brother sold their interest in the company for $2.7 million in 1961 to Ray Kroc, who is credited with building the company into an eating empire.

The number of hamburgers McDonald's has sold over the years is matched only by the number of "McFacts" about those numbers dispensed by company officials. For example: The company sells a couple of thousand burgers every few seconds; 7 percent of American adults eat at a McDonald's daily, and McDonald's serves food to the equivalent of the world's population every nine months.

But the latest McNugget of information came hot off the griddle today: It may have taken the company 36 years to sell 50 billion burgers, but company planners are already projecting the date on which the 100 billionth burger will be served: May 13, 1993.