In this lesson, students apply their knowledge of volume of rectangular prisms to find volume of composite solids. They work in pairs to build different solids with unit cubes and find individual volumes. For example, one partner's solid has a volume of 8 cm^3 and the other partner has a solid with volume 12 cm^3. Then they will combine their solids to build a new solid and find the volume of that solid. Finally, they will apply what they have learned to calculate volume of visually represented solid figures.