Many teachers labor to distinguish between productive and unproductive struggle; they believe that struggle is productive when it engages students in thinking and communicating metacognitively, which is when students think and communicate about their problem-solving processes, strategies, challenges, and successes. One method that helps ensure that students' struggles are productive is the Spend a Buck strategy (Kagan 2001). In this article, a teacher uses this technique as a way to deepen student thinking about strategies for solving systems of equations. His students not only build a better understanding of mathematics but also--by engaging in the Spend a Buck strategy--develop their communicative and metacognitive skills. By illustrating Spend a Buck in action in the classroom, the authors hope to inspire others to incorporate more communicative activities in their own classrooms and to identify more activities that encourage communication and metacognition through discourse to use with their students. Doing so will help students build critical communicative and metacognitive abilities in addition to enhancing their mathematical understanding. With practice, Spend a Buck helps students be more effective in their communication and metacognition and, in turn, more successful students of mathematics.