hiː ðˈɛn sˈɜːvd æz ðə hˈɛd ʌvðə mˌæθɪmˈæɾɪks dᵻpˈɑːɹtmənt æt ðə jˌuːnɪvˈɜːsᵻɾi ʌv bˈɛnɪn ɪn naɪdʒˈiəɹɪə ʌntˈɪl nˈaɪntiːnhˈʌndɹɪd sˈɛvənti sˈɛvən, wˌɛn hiː ɹᵻtˈaɪɚd.
He then served as the head of the mathematics department at the University of Benin in Nigeria until 1977, when he retired.