A group of mathematics educators set out to explore lesson study and fraction division. During the first implementation of the lesson, which we researched and created, we grappled with standard protocol for lesson study. What are the advantages and disadvantages of listening silently? When/why should teachers adhere strictly (to the lesson plan) or when/why should they allow for veering? If the lesson study group is silent and the teacher adheres to the plan, then opportunities for exploring other big mathematical ideas can potentially be lost in the implementation. The teacher’s own inner voice [1] can be compromised. In what ways might lesson study coerce teachers to listen primarily to the voice of the lesson plan by assuming the voice of the discipline and the voices of the students were “built in” prior to the lesson implementation? In this article, we describe, through narrative and transcripts, when/why we ultimately chose to deal with these questions.

lesson study, fraction division, teacher education.