The intent of this monograph is to showcase successful implementation of mathematical discourse in the classroom. Some questions that might be addressed are: * How does a teacher begin to learn about using discourse purposefully to improve mathematics teaching and learning? * How is discourse interwoven into professional development content courses to provide teachers with the tools necessary to begin using discourse in their own classrooms? * What does a discourse-rich classroom look like and how is it different from other classrooms, from both the teacher's and the students' perspectives? * How can teachers of pre-service teachers integrate discourse into their content and methods courses? * How can we use discourse research to inform work with teachers, both pre- and in-service, for example, to help them know how to respond to elicited knowledge from students in their classrooms? * What are the discourse challenges in on-line mathematics courses offered for professional development? Can on-line classrooms also be discourse-rich? What would that look like? * In what ways does mathematical discourse differ from discourse in general?