 Adler taught mathematics at various New York City high schools during the 1930s and 1940s.He was chair of the math department at Straubenmuller Textile High School from 1946 until 1952.He was also an active member of the New York City Teachers Union, Local 5 of the American Federation of Teachers, and was drafted into a leadership role as a member of its executive board, chairman of the educational policy committee, and then as chairman of the salary and legislative committee.