In this paper we investigate the translation of research into professional development (PD) materials for teachers of primary mathematics, by England's National Centre for Excellence in the Teaching of Mathematics, and related changes in teacher practices of teachers using the materials. We use interview data gathered from three teachers, via six teacher interviews, conducted over a two-year period. The small sample allows us to explore the richness of their stories, while not being able to generalise to all teachers. Our results show that both implicit and explicit messages from research can become visible in new classroom practices. For instance, the teachers in our study all came to view the concept of number quite differently to how they had in the past, and in a way that was in keeping with research that informed the PD materials. A new view of number was implicit in the PD materials and in the teachers' descriptions of their practice. Other changes in teaching practices were explicitly spoken about by the teachers and were explicitly written about in the PD materials. Our work points to the efficacy of a team of practitioners working, with guidance, to create practical resources which embody research results. We propose viewing teachers as active partners in the process of translating research into practice.