Students know the volume formula for a sphere as it relates to a right circular cylinder with the same diameter and height. Students apply the formula for the volume of a sphere to real-world and mathematical problems. The demonstrations in this lesson require a sphere (preferably one that can be filled with water, sand, or rice) and a right circular cylinder with the same diameter and height as the diameter of the sphere. Demonstrate to students that the volume of a sphere is two-thirds the volume of the circumscribing cylinder.