This unique classroom set of base ten componen ts 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 set is washable and durable for years of hands-on activities. Great for whole-class instruction, small groups, centers or individual exploration. Boxed set features 600 units, 200 rods, 20 flats, 3 cubes and 112-page Base Ten Book filled with teaching ideas.