Assessment and instruction are interwoven in mathematically rich formative assessment tasks, so employing these tasks in the classrooms is an exciting and time-efficient opportunity. To provide a window into how these tasks work in the classroom, this article analyzes summaries of student work on such a task and considers several students' solution strategies to exhibit the usefulness of these tasks in assessment, learning, and teaching in the classroom. This article also provides some guidance on implementing these tasks in the classroom.