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.
The Girl Who Never Made Mistakes. great for teaching that mistakes are ok.and how to learn from mistakes. So great for setting up a positive learning environment. Good for beginning of year or FHE lesson.