These Rekenrek cards are 1/4 sheet each and represent numbers 1-20. This powerful tool color codes the beads with five red and then five white in each row so that students can subitize (instantly recognize the number) This also help students break numbers apart into fives and tens so that they can make friendly numbers. There are several different rekenreks, starting with a ten, a twenty, and then a hundred. This tool is very powerful for computation and can be used with the math manipulative. You can buy them from enasco and they are really well made!