Policy documents and researchers agree that proofs and proving should become common mathematical practice in school mathematics. Towards this end, teachers are encouraged to implement proving activities in their classrooms. This article suggests a tool that may help teachers to integrate proofs and proving in their practice--the six-cell matrix. In addition to presenting the tool, we demonstrate how the tool may be used by teachers in four phases of their practice: planning a sequence of lessons, during a lesson, as an assessment tool, and as a way of making sense of learning materials. (Contains 3 tables and 1 figure.)