Cuisenaire Rods help students transition from concrete to abstract representation of math concepts. Each colour represents a different Rod length that can be assigned a different numeric value or unit of measure. Great for improving skills such as fractions, measurement and more. Rods measure 1cm - 10cm in length. Grades Pre K+. Small Group Set contains 155 durable rods for use with 4-6 students. Classroom Set contains six sets of 74 durable rods for use with 12-18 students.