Our research focuses on a growth model of teachers’ ability to assess student learning as a result of creating equitable instruction for students in informal school settings. We describe data collected as part of a study examining the mathematical reasoning of Grades 3–5 students. Our research context took place in six elementary schools from rural and urban settings. Here, we focus on one of the schools by describing how a teacher began her instruction and over time, how she developed her assessment strategies to ensure that students obtained access to and support for algebraic reasoning, mathematical content, and discourse
