Our position in this paper is that students participating in mathematics classrooms are initiated into a local discourse that might be called “the discourse of the mathematics classroom.” The discourse of one mathematics classroom may differ significantly from the discourse of another, both in terms of the mathematical sophistication of the terminology employed and in the relative prioritisation and authority accorded to the voices of the teacher and the students. The implicit assumption guiding instruction in the classrooms studied in Hong Kong and Seoul seems to be that the employment of spoken mathematics by students is not to the benefit of the students' learning of mathematics. Classrooms studied in Melbourne, Berlin, Tokyo, San Diego, Singapore and Shanghai, despite differences in implementation, seem to make the opposite assumption. Although culture frames classroom discourse and expectations of classroom practice, both sets of pedagogical aspirations seem able to be realised in classrooms that appear to reflect many cultural similarities. Spoken mathematics provides a window into the fascinating dialectic between cultural norms and pedagogical values.