This Instructional Activity is a part of the Lesson 19, Unit 6, Grade 7. Students are to imagine each three-dimensional figure as a figure built on a tabletop. Each horizontal slice of the figure is to be mapped onto grid paper where each cell represents the base of a unit cube. Level means the slicing plane is units above the tabletop. Thimeans that Level 0 is the level of the tabletop, while Level 1 is one unit above the tabletop.