These Teacher Notes from Student Explorations in Mathematics (NCTM) describe a series of activities that begins with the arch problem found in Unit 8 of the CUNY Framework. From there, students move onto into three other visual patterns. There is a strong emphasis in these notes for students to come up with different equations to describe the changing patterns. I really like the extension activities, including students coming up with their own visual patterns given an equation and work with non-linear functions using the perfect squares. These are a really great supplemental materials for anyone who is using the visual pattern approach to developing students’ algebraic reasoning.