Learning Resources Grooved Plastic Base Ten Starter 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 3 to 4 students. Versatile set includes 100 units, 30 rods, 10 flats and 1 whole cube. Includes 112 page activity book. Suitable for ages 6+