The rekenrek is a abacus-like math learning tool that both my kids have used in their early math education. This version was designed to be easily assembled with a #2 pencil. The racks can be attached to each other with small nibs. Typically, a rekenrek has two rows with ten beads (2 color groups of 5) that are fixed. But with this design, kids can add and remove the beads, depending on the exercise and complexity level. The beads range from 1-10 sides, representing different numbers. You can position multiple racks horizontally or vertically, and incorporate any number of beads for a fun range of exercises around number concepts, addition, subtraction, as well as multiplication. Since #2 pencils might be scarce in many classrooms, there's a small hole at either end (with grooves on the bottom and sides) for a string. Note: the pieces are uploaded individually as it gives the most flexibility for grouping prints. The pieces are listed with their numbers as "w" for with number and "wo" for without number. Figured I'd just give folks the choice. More info on my blog. Facebook Twitter Lots of Rekenrek activities can be found here.