In this article, the authors focus on using board work to scaffold what they call "joint sense making," because effective mathematics instruction is, at its heart, characterized by teachers and students engaging collaboratively in making sense of mathematical ideas (National Council of Teachers of Mathematics, 2009, 2014). This sense making involves students grappling with a mathematical situation and responding to their peers' thinking about that situation, and teachers helping to facilitate that activity while avoiding the temptation to do the sense making for the students. From their experiences working together with middle and high school mathematics teachers to learn how to more productively use student mathematical thinking (see Peterson et al., 2022; Stockero et al., 2014; Van Zoest et al., 2023), the authors have gained insights into how public records have the potential to help teachers overcome some of them challenges of that work. In this article, the authors share these insights by providing suggestions for how teachers can productively use a public record to scaffold joint sense making.