Description: Topic C is designed to deepen students' understanding of spatial structuring as they build and partition rectangles with rows and columns of same-size squares. In Lessons 10 and 11, students compose a rectangle by making tile arrays with no gaps or overlaps. They use their prior knowledge of making equal groups and the spatial relationship between rows and columns to construct rectangular arrays. Lesson 12 introduces the added complexity of composing a rectangle by using math drawings. After students compose rectangles, they decompose, or partition, them using tiles in Lesson 13. In Lesson 14, students are encouraged to think flexibly as they use paper models to further develop their ability to visualize arrays. Lesson 15 moves toward more abstract reasoning as students use math drawings to partition rectangles. In Lesson 16, students practice spatial structuring skills by working with grids and diagrams.*Teacher Advisor is 100% free.