Vol. 18 Num. 1 (1998) David Pimm Editorial2 Bill Barton ,  Uenuku Fairhall ,  Tony Trinick Tikanga reo tatai: issues in the development of a Maori mathematics register3 Tamsin Roberts Mathematical registers in Aboriginal languages10 Carl Winsløw A linguistic approach to the justification problem in mathematics education17 Jill Adler A language of teaching dilemmas: unlocking the complex multilingual secondary mathematics classroom24 Mamokgethi Setati Code-switching in a senior primary class of second-language mathematics learners34 Anna Sfard ,  Pearla Nesher ,  Leen Streefland ,  Paul Cobb ,  John Mason Learning mathematics through conversation: is it as good as they say?41