3 years & up. Children will have fun creating pictures and games with this set of 20 jumbo chalk sticks in a handy storage bucket that is great for on-the-go fun. Chalk can be used indoors or outdoors on chalkboards, sidewalks, or asphalt. When they are finished with their creations, chalk can be easily washed away with water. Jumbo chalk is easy for little hands to hold and comes in four fun colors: white, red, green, and blue. Conforms to ASTM D4236.