Reforms in education have repeatedly been confronted with the challenge of policy implementation. Recent initiatives in mathematics are no exception. Pressing for fundamental and complex changes to pedagogy, the initiatives demand much from teachers. In this article, we propose a conceptual frame for understanding how teachers and schools work to transform instructional practice. In integrating two aspects usually considered independently in research, we explore the way in which teachers make sense of the reforms, and the means by which schools make implementation possible for teachers. Our investigation focuses on two teachers, and explores how both attempt to enact the spirit of a national numeracy project. The exploration provides important insights about patterns of change in pedagogy that follow on from large-scale reform. (Contains 1 footnote.)