How to keep a child busy for hours in the summer: DIY: Giant Ice Cube Awesomeness - filled with plastic animals, dinos, and such. And I'm sure you could put in food dye before its frozen to color it like the ice block in the photo.
SUMMER THEME Puffy Ice cream- glue and shaving cream. Also, leave paint white and paint on black ghost shapes for Halloween. Remove eye and mouth holes with q-tip or black paper ovals will stick to glue/shave cream mixture