As part of lesson 8, students used same-size squares to compose rectangles. This lesson places student learning wholly in the domain of standard 2.G.2 because, rather than composing a rectangle, students are partitioning a rectangle into same-size squares and then counting the squares to find the total number. They continue to see these square arrangements as a series of rows or columns because this allows them to use repeated addition as a counting method. Students develop their ability to use tools strategically by using only one tile and a pencil to cover the rectangle's area.