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. Small Group Set Contains 155 wooden rods and Activity Guide in a storage bucket. (50 white, 25 red, 16 light green, 12 purple, 10 yellow, eight dark green, seven black, eight brown, nine blue, and 10 orange rods). Great for 4-6 students. Classroom Set contains six sets of 74 rods, six trays with lid and Teacher's Guide. Great for 12–18 students. Grades Pre K+.