Learning Resources Base Ten Interlocking Plastic Rods Starter Set. Help students understand abstract base ten concepts including place value, estimation, operations, fractions and more. These Base Ten units are made of durable plastic. Set includes 100 units, 30 rods, ten flats, a cube and 112 page activity book. Suitable for ages 6+. Need more? Take a look at the Learning Resources Base Ten Interlocking Plastic Rods Class Set for 20 – 25 students (available separately)