Donald Jay (Donnie) Mash, 11, a fifth grade student at Green Acres Elementary school in Fairfax who also was active in Little League baseball, died Jan. 30 at Fairfax Hospital where he had been undergoing treatment for cancer.

A pitcher for the Dragons, in the Dominion AA East Division of the Fairfax Little League for Summer, he also played first base and other infield positions.

In 1978, Donnie was chosen "Outstanding Player" in his division. He led the division with a.737 season's batting average and pitched the entire final and winning game of the championship series between the Dragons and the Deuces. He also went four-for-four at bat in the final game.

Before his illness, he had run three miles every other day.

At school, Donnie qualified for a special program for gifted and talented children.

He was born in Olean, N.Y. He moved to Fairfax in 1975 when his father, Donald P. Mash, became vice president for student affairs at George Mason University.

Donnie's hobbies were following the Pittsburgh Pirates and the Pittsburgh Steelers and constructing model airplanes and rockets.

In addition to his father, he is survived by his mother, Julia M., and two sisters, Maria Christine, and Christina Lynn, all of the home in Fairfax; his grandmother, Christine Mash, of Jeannette, Pa., and his grandparents, Mr. and Mrs. H. A. Larson of Clearwater, Fal.

The family suggests that experssions of sympathy in the form of contributions to the American Cancer Society.