4 cups dried, used coffee grounds*, 2 cups cornmeal, 1 cup flour, 1/2 cup salt ** Note that coffee grounds must be extremely, 100% dry or else the mixture will not mix well and will turn moldy. Dry in the oven on low heat, or outside in the sun.
Make sand at home! Half the fun is creating, and half is playing with the material. Mix all listed ingredients together in a plastic bin, and then give your child small containers, shovels, funnels so that they can dump and fill. Toy cars and bulldozers are also a lot of fun.