When the author recently turned her attention to the National Council of Teachers of Mathematics (NCTM) "Principles and Standards," she was startled to see communication as key. She adjusted her teaching to meet the NCTM Communication Standard and promote communication in her classroom by providing a safe environment, developing discourse and writing, and expecting students to listen and question one another. She found this idea compelling: she could teach her students to argue and justify their mathematical thinking in much the same way that they support their theses in her writing classes. As students became accustomed to her mantra, they began to explain their thinking before she asked. In this article, the author shares how making communication a priority can influence students' learning by helping them elucidate misconceptions and make meaningful mathematical connections. (Contains 8 figures and 1 table.)