On 14 December 1931, with the help of Norbert Wiener, Hopf joined the Department of Mathematics of the Massachusetts Institute of Technology accepting the position of Assistant Professor. Initially he had a three years contract but this was subsequently extended to four years (1931 to 1936).
Sa 14 ng Disyembre 1931, sa tulong ng Norbert Wiener, Hopf sumali sa Kagawaran ng Matematika ng Massachusetts Institute of Technology tanggapin ang posisyon ng Assistant Professor. Sa simula pa niya ng isang tatlong taong kontrata ngunit ito ay sa dakong huli pinalawig sa apat na taon (1931-1936).