You can use a slow cooker to turn broken crayons into fresh art supplies, with the help of inexpensive silicone molds that you can buy at craft stores. Sort your old crayons by color family, and remove the paper wrapping. Place the broken bits of a single color into the slow cooker, and heat on low until the pieces have melted. Pour or ladle the melted crayons into silicone molds, and place them in a cool, dry location until they've cooled completely. Then, break out the coloring sheets and set the little ones to work.