As mathematics classrooms are becoming more and more diverse, teachers aiming to help all of their students learn are increasingly challenged. Pandemic-related learning gaps, the arrival of newcomers who may have experienced interrupted schooling, and the increase in the number of students with disabilities in general education classrooms have intensified performance differences among students. It is widely recognized that teachers require help and support to meet the varied needs of the different students they serve. There is less certainty, however, about the kind of support that will help teachers to make this happen.