Knowing how gestures may enhance communication during instruction is critical to developing robust learning environments. I will present how gesture may enhance communication in the first semester calculus classroom by considering the nature of gestures used by instructors and students. First, we will explore how instructors use gesture to highlight important mathematical information while making connections among representations of concepts. This will be examined in the context of optimization and the second derivative test. Second, we will examine how gesture use facilitated the problem-solving process for a pair of students solving an optimization problem. The students’ gesture production increased when students were solving problems that involved non-standard geometric shapes, as did the number of interactions with and revisions to their diagrams. From these findings, we conclude that gesture production during instruction and students’ problem-solving processes can help students make connections and extensions between ideas.