This paper reports research into the nature and occurrence of the spoken use of technical mathematical terms in well-taught classrooms in Berlin, Hong Kong, Melbourne, San Diego, Seoul, Shanghai, and Tokyo. The analysis determined the number of utterances occurring in whole class and teacher-student interactions in a sequence of five lessons from each of the classrooms studied (a total of 95 lessons from nineteen classrooms), together with the frequency of public statement of mathematical terms and, in a separate analysis, the number of utterances and spoken mathematical terms in the context of student-student (rather than public) interactions. Also analyzed was student use of technical mathematical terms in 176 post-lesson interviews in which they described classroom activities and their mathematics learning. Student-student spoken interactions were frequent in classrooms studied in Berlin, Melbourne, and San Diego, and non-existent in Shanghai and Seoul. The variation between the classrooms studied in Seoul, Shanghai, Hong Kong and Tokyo problematises any simplistic characterization of “the Asian classroom.” Our results demonstrate that student spoken facility with the technical language of mathematics requires deliberate scaffolding and, interestingly, this can be achieved through either public or private discourse. Student facility with spoken mathematical terminology varied significantly.