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.
Why do we add S to some words but ES to others? And when a word ends with Y, how do we know whether to change the Y to I before adding the plural suffix? And why on earth does knife become knives? You can unravel these mysteries with six simple rules.