This article is a report on the findings of three case studies that focused on elementary teachers' in-the-moment noticing across a month of instruction. Extending Jacobs and her colleagues' framework (Jacobs, Lamb, and Philipp, 2010), this articles categorizes the mediums (i.e., written accounts, verbal interactions, physical strategies) by which the teachers attended to their students' mathematical reasoning. Even though the teachers taught similar lessons, they attended to students' actions through different mediums. These mediums reflected and often aligned with individual teaching practices and routines. More interestingly, the teachers' preferred medium was also the most productive for them in terms of discussing students' understanding and informing instructional decisions. [For the complete proceedings, see ED583989.]