Sister Cecilia Navin, O.S.U. , a longtime teacher at the Academy of Mount St. Ursula in the Bronx and other schools in the archdiocese, died Oct. 18 at Andrus House in Hastings-on-Hudson. She was 97. She taught mathematics at the Academy of Mount St. Ursula from 1943 to 1976. She also taught at St. Jerome's School, the Bronx, 1940-1943; St. Joseph's, Middletown, 1938-1940; and the Ursuline School, New Rochelle, 1933-1938. She was assistant superior of the Ursuline Bedford Park Convent, 1961-1966, and tended the grounds and did maintenance work there from 1966 until her retirement in 1976. She resided at the convent until 2002. Born in the Bronx, she entered the Ursuline Sisters in 1930 and made final vows in 1936. She held a bachelor's in mathematics from the College of New Rochelle and a master's from Fordham University. A Funeral Mass was offered Oct. 21 at Ursuline Bedford Park convent. Burial was in St. Raymond's Cemetery.