Vol. 29 Num. 2 (2009) Anderson Norton Re-solving the learning paradox: epistemological and ontological questions for radical constructivism ABSTRACT 2 Tony Wing The post-Piagetian child: Early mathematical developments and a role for structured materials ABSTRACT 8 Cristina Frade , Peter Winbourne , Selma Moura Braga A mathematics-science community or practice: Reconceptualising transfer in terms of crossing boundaries ABSTRACT 14 David Pimm , Nathalie Sinclair Audience, Style and Criticism ABSTRACT 23 Susan Staats Communication: Comment on "Audience, style and criticism"28 Giorgio T. Bagni Communication: Bombelli's Algebra (1572) and a new mathematical object29 John Mason , Anne Watson The Menousa ABSTRACT 32 Peter Appelbaum Taking Action - mathematics curricular organization for effective teaching and learning ABSTRACT 38 - Contributor affiliations and contact information44