Mathematics is a language that is characterized by words and symbols that have precise definitions. Many opportunities exist for miscommunication in mathematics if the words and symbols are interpreted incorrectly or used in imprecise ways. In fact, it is found that imprecision is a common source of mathematical disagreements and misunderstandings between students, as well as between students and teacher. To help students learn to communicate more precisely, the authors devised an activity called a Communication Game that involved relating trips along a number line to arithmetic equations. A key feature of this game is that it places students in situations that require precise communication with their classmates. Students find out for themselves how successfully they communicated, and they give feedback to their peers to help them communicate more precisely in the future. Communication Games, more broadly, can be incorporated in different mathematical domains.