This article examines how a coding scheme for mathematics classroom discussion that was created to highlight how teachers negotiate student responses during whole-class discussion around high-level, cognitively demanding tasks was used to help teachers shift what they notice when analyzing classroom discourse. Data from an intervention that trained teachers how to use the coding scheme and then provided them opportunities to use the scheme to code transcripts of classroom discussion are presented. Results suggest that teachers' ability to notice interactions between teacher and students when analyzing classroom discussion (as opposed to focusing on one actor or the other) can be increased and that teachers can learn to identify specific discourse moves teachers use to negotiate student responses. However, teachers' capacity to identify how students' opportunities to learn are related to teacher discourse moves did not change as a result of the intervention. The article goes on to examine how discussion during the intervention itself may have contributed to what teachers learned to notice. This research contributes to the body of work on teachers' noticing by examining the feasibility and efficacy of using transcripts and a coding scheme to foster teachers' ability to notice how they can increase their students' opportunities to learn through mathematics discourse.