Concrete way to explore geometry, volume and other measurement concepts. Removable bases allow for relating 2-D shapes to 3-D solids. Easy to fill with liquid or dry-fill, and easy to clean. Includes large triangular pyramid, square pyramid, hemisphere, sphere, cone, pentagonal prism, small and large cube; rectangular prism, triangular prism and cylinder. Colorful plastic shapes measure 3 cm or 6 cm and includes Activity Guide with formulas and interventions. Grades 3+ . Set of 14.