Learning Resources LER6356 Interlocking Base Ten Starter Set Units are made of durable, washable plastic for years of hands-on activities Help students understand abstract base ten concepts; including place value, estimation, operations and fractions 141 pieces include: 100 units, 30 rods, 10 flats, 1 cube, and 96-page Base Ten Activity Book Starter set perfect for use with 3-4 students Ideal for ages 6+