This unique set of 100 base ten units conveniently interlocks to clarify place value, estimation, and operations concepts by enabling students to manipulate and visualize varying quantities with ease. More advanced students can explore spatial relationships and volume. Plastic 1 x 1 x 1 cm units are washable and durable for years of hands-on activities. Use with Interlocking Base Ten Rods, Flats and Cube.