\input zb-basic \input zb-matheduc \iteman{ZMATH 2011a.00273} \itemau{Zahner, William; Moschkovich, Judit} \itemti{The social organization of a middle school mathematics group discussion.} \itemso{Lesh, Richard (ed.) et al., Modeling students' mathematical modeling competencies. ICTMA 13. Proceedings of the 13th international conference on the teaching of mathematical modelling and applications, July 22--26, 2007. London: Springer (ISBN 978-1-4419-0560-4/hbk; 978-1-4419-0561-1/ebook). 373-383 (2010).} \itemab Summary: This study analyzes patterns of interaction among bilingual middle school students while they engaged in peer mathematical discussions. Using a sociocultural lens on learning the practice of school mathematics, this study addresses three questions: (1) What kind of mathematical discourse practices did the students engage in? (2) What discourse patterns emerged during these mathematics conversations? (3) What are the implicit ``rules" that appear shape students interactions, what are the pragmatic implications of these rules, and which students benefit from these rules? Using conversation analysis and discourse analysis we show that the students primarily engaged in ``calculational" conversations, that mathematics conversations followed rules distinct from the rules of everyday conversations, and ``intellectual authority" emerged as an important construct for understanding students mathematical discourse practices. \itemrv{~} \itemcc{C53} \itemut{student student interaction; bilingualism; bilingual classrooms} \itemli{doi:10.1007/978-1-4419-0561-1\_32} \end