To Demonstrate conservation of size, by providing different shapes that hold the same ratio volume. Opening provided for easy filling. Includes 6 clear solids: cone, sphere, cylinder, cube, pyramid as well as rectangular prisms. Pyramid: 10cm square, Rectangular Prism: 10 x 5 x 10cm tall, Cylinder: 10 x 10cm, Square Prism: 10cm cube, Sphere: 10cm diameter, Cone: 10cm diameter. Ages 6+ years.