I bought a bag of M&M's to do math with William and Luke the other day. Funny how chocolate can motivate just about anyone!
First, I asked them to sort their M&M's into groups of the same color.
Then, they had to count how many they had of each color, working with one color at a time.
I would ask them who had more of that color and who had less.
Then whoever had more, had to figure out how many he had to eat to make it the same number.
Once they had all the same number M&M's in each color, I let them start eating them at will. But we also had fun making patterns with them: GREEN - YELLOW-BROWN, GREEN-YELLOW-BROWN. It was really fun and they now look forward to doing math every day (even if we don't always have M&M's laying around.