Vol. 38 Num. 3 (2018) - front cover0 Vanessa Sena Tomaz ,  Maria Manuela David Mathematical artifacts as communicational facilitators between indigenous and non-indigenous cultures ABSTRACT 2 Mulia Putra How ethnomathematics can bridge informal and formal mathematics in mathematics learning process at school: a framework11 David A. Reid ,  Mellony Graven ,  Jean-François Maheux Conversation14 Anna Sierpinska Communication: Response to Culligan and Wagner’s ‘This is not mathematics’16 Rod E. Case ,  Gwendolyn Williams ,  Peter Cobin Metaphor and problem-solving among English language learners16 Alf Coles On observing mathematics teacher learning ABSTRACT 19 Sean Larsen Didactical phenomenology: the engine that drives Realistic Mathematics Education ABSTRACT 25 Andrea Maffia ,  Maria Alessandra Mariotti Intuitive and formal models of whole number multiplication: relations and emerging structures ABSTRACT MORE INFORMATION   30 Teo Paoletti ,  Kevin C. Moore A covariational understanding of function: putting a horse before the cart ABSTRACT 37 Brent Davis What sort of science is didactics? ABSTRACT 44 Maria G. Bartolini Bussi Answer to Gascón & Nicolás ABSTRACT 50 Stephen Lerman Communication: Towards subjective truths in mathematics education54 Jérôme Proulx Communication: Prescriptions and proscriptions on mathematics teaching: interesting cases of lost in translation56 - Contributor affiliations and contact information58