Instead of numbers write the color word on the bottles. Sort pom-poms by color. Empty each bottle and count the pom-poms. Then record how many pom-poms were in each bottle. Add the two colors together for addition practice.
Clothespin Math on a clothes hanger! LOVE this. Easy to make, and self explanatory. I'm thinking a wire clothes hanger would work better, so the clothes pins are easy to slide back and forth (almost like an abacus).