Secondary-tertiary transition issues are explored from the perspective of ways of doing mathematics that are constituted in the implicit aspects of teachers' action. Theories of culture (Hall, 1959) and ethnomethodology (Garfinkel, 1967) provide us with a basis for describing and explicating the ways of doing mathematics specific to each teaching level, according to the "accounts" provided by the teachers involved in this research project. To borrow from Hall (1959), the "informal" mode of mathematical culture specific to each teaching level plays a key role in attempts to better grasp transition issues.