Set it up. This works best if you set up the experiment after a trip to the playground and before they wash their hands.
Ask child to “wipe” off his or her hands to get rid of visible dirt. (Most children believe this is clean enough!)
Help your child use the permanent marker to label three sandwich bags: “Clean Hands” “Dirty Hands” and “Control.”
Use the tongs to remove a slice of bread from the wrapped loaf and place in the sandwich bag marked “Control.”
Take another slice of bread and rub his or her hands thoroughly on both sides of the bread. He or she should put this slice into the bag labelled “Dirty Hands.” Zip the bags and tape or place on a shelf or inside a cupboard. Check the bags every few days. Which one grows the most mold first?