A rekenrek is a powerful tool for teaching counting and pre-counting concepts to young learners. The rekenrek combines a number of tools (number line, groups of five and ten, single counters) into one package that allows users to get a hands on feel for manipulating numbers.
Rekenrek for iPad is meant for classroom use, and uses a physics engine to achieve a realistic look-and-feel. Although the rekenrek traditionally contains only two strings, Rekenrek for iPad allows the user to show or hide from 1 to 5 strings of 10 beads.