Using an air popper, make several batches of popcorn. When the popcorn has cooled off, have the children split the popcorn up into several zip loc bags. Pour melted butter into each bag. Sprinkle a dry ingredient into the bags, close the top, and have your children shake it.
Some choices for dry ingredients are Cinnamon, sugar, dry ranch, dry cheese, garlic, etc.
Have your children choose which one they like best and graph the results.. Everything Preschool >> Themes  >> Popcorn >> More