Classroom discourse is a valuable teaching and learning tool. Discussions allow students to improve their communication and reasoning skills in mathematics and help teachers assess students' understanding of mathematical ideas. To get the greatest benefit from discussion, teachers must elicit student thinking, listen carefully to their ideas, and ask them to clarify and justify their thoughts. This article describes examples of discursive moves that a teacher performed in several seventh-grade pre-algebra classes. These examples illustrate the opportunities for learning that the teacher provided when leading a class discussion. In all the episodes, the teacher was leading a discussion of a homework assignment about functions and linear equations, which occurred before the topics were formally taught. This article focuses on two discursive moves that the teacher performed when leading the discussion: request an explanation and orient. The names of the different types of discursive moves convey the types of actions that the teacher performed to promote students' reasoning and sense making. The article also proposes alternative statements or questions that a teacher may pose in these situations.