This set includes two plastic tracks, numbered from 1 to 100, and 50 rods that slide along the center of the track. It is used to develop skills in counting, sorting, sequencing, pattern recognition, measuring, addition, and subtraction. Details:Visual and hands-on math learningCompatible with Kids First Math Number RodsDurable plastic for long-term use and easy cleaningFor ages 3 and upContents:1 plastic storage box1 lesson guide2 plastic tracks, numbered from 1 to 10010 number track pieces in 2 colors50 sliding rods (1-cm to 10-cm in length, each in 5 colors)