Robert John Hill Jr., 64, a retired Army colonel who became an administrator and part-time teacher in the mathematics department at the University of Maryland, died June 3 at Walter Reed Army Medical Center following heart surgery.

Col. Hill, who was born in Park Ridge, Ill, graduated from the U.S. Military Academy at West Point, N.Y., in 1939. During World War II, he commanded a field artillery battalion in Europe. His postwar assignments included the Army War College, from which he graduated, command of an artillery group at Fort Sill, Okla., and service in Taiwan.

From 1960 until his retirement in 1966, he was assigned to the office of the deputy chief of staff for operations of the Army in the Pentagon.

Col. Hill later joined the University of Maryland, where he was an administrator and teacher until his second time in 1979. He lived in Adelphi.

His military decorations include the Silver Star, the Bronze Star, the Legion of Merit and the Army Commendation Medal.

He was an elder and a chairman of the board at the Wallace Memorial Presbyterian Church in Hyattsville.

Survivors include his wife, Hazel M. of Adelphi; three sons, Robert J., of Potomac, T. R., of Charlottesville, Va., and James of Charleston, S.C.; two daughters, Virginia Brow of Fairfax, and Patricia Hill of Washington; two sisters, Rita Oechsel and Lois Smith, both of Chicago, and three grandchildren.