Learning Resources Grooved Plastic Base Ten Class Set. Help students understand abstract base ten concepts including place value, estimation, operations and fractions. Blue units are made of durable plastic. Set includes enough maths manipulative for use with 20 to 25 students. Versatile set includes 600 units, 200 rods, 20 flats and 3 whole cubes. Includes 112 page activity book. Suitable for ages 6+