Vol. 27 Num. 1 (2007) Laurinda Brown Editorial changes2 Susan Staats Dynamic contexts and imagined worlds: an interdisciplinary approach to mathematics applications ABSTRACT 4 Daniel Clark Orey , Milton Rosa Cultural assertions and challenges towards pedagogical action of an Ethnomathematics program ABSTRACT 10 Karin Brodie Teaching with conversations: beginnings and endings ABSTRACT 17 Judit Moschkovich Examining mathematical Discourse practices ABSTRACT 24 David Pimm Communication: Registering surprise31 Richard Barwell Communication: Semiotic resources for doing and learning mathematics32 Cinzia Bonotto The Erlangen program revisited: a didactic perspective ABSTRACT 33 Gustavo Barallobres Introduction à l'algèbre par la généralisation : problèmes didactiques soulevés ABSTRACT 39 Monica Johansson Mathematical meaning making and textbook task ABSTRACT 45