This article presents findings from research on a field experience designed to help elementary preservice teachers learn the practice of teacher questioning during formal and informal interviews to analyze student mathematical thinking in K-2 classrooms. The practice of teacher questioning is framed as choosing a mathematical goal, analyzing student thinking about that goal, and then deciding on a question or prompt. Preservice teachers were specific and accurate in identifying a mathematical goal and analyzing student thinking when responding to a video-taped interview, but were less successful in their explicit discussion about the rationales for particular teacher questions in response to student thinking. More research is needed to understand tasks for preservice teachers in early field experiences that will help them develop intentional use of teacher questioning to facilitate student thinking about mathematics.