This is an optional lesson because it revisits content learned in previous grades. In this lesson, students calculate the volume of prisms, cylinders, cones, and spheres, and apply this understanding to composite figures. First, students explore the relationship between the base area of a prism or a cylinder and its volume. Next, students apply volume formulas to cones, spheres, and cylinders. Students look for and make use of structure (MP7) when using formulas to calculate volume and find unknown dimensions of solids. Finally, students apply their understanding of volume calculations to composite shapes in an applied context.