Fostering Middle School Teachers' Mathematical Knowledge for Teaching via Analysis of Tasks and Student Work

Mathematical knowledge for teaching is a complex web of knowledge domains. In this article, we share findings from an 18-month professional development project that aimed to improve middle school mathematics teachers' mathematical knowledge for teaching (MKT) of proportional reasoning by focusing on the critical analysis of mathematical tasks and student work. Although multiple studies have shown that professional development can contribute to teachers' MKT globally, little is known about how this knowledge grows and how specific domains of MKT can be targeted through professional development. Findings in this study show how professional development positively influenced participants' knowledge of content and teaching and knowledge of content and students, two domains of MKT, through teachers' twinned analyses of tasks and student work in proportional reasoning.