This study describes the Reflection Connection Cycle professional development program. The author chose to develop a program that would help teachers find ways to draw on the knowledge students gained from their out-of-school experiences for the explicit goal of using those understandings to support classroom mathematics learning. The participants were 14 female elementary school teachers. The findings revealed that while initial lessons focused solely on the context of practices, subsequent lessons show a greater concern for the mathematics in which children were engaged within a practice. The author argues that specific support in making connections to informal understanding in lesson design may need to be addressed directly.