The central concerns of this chapter are the examples and accompanying explanations teachers offer as they elaborate mathematical ideas in their classrooms. We contend that these two commonplace features of mathematics teaching are critical elements of what we have come to describe as teachers’ mathematical discourse in instruction (MDI). In previous writing (Venkat & Adler, 2012), we focused on MDI through the representations, transformations and accompanying explanations given by teachers as they worked with specific examples.