The Rekenrek, Abacus, or Counting Frame is a tool for aiding and displaying a wide range of number-related problems such as counting, addition, and subtraction. It helps students to understand number structures. You can use it with the traditional red and white beads for a 5-based structure, with a 10-based structure or even with various other colors. Move the beads from left to right or vice versa to demonstrate basic operations.
