You may want to make homemade trail mix using wholegrain cereals and dried fruits. You could include sunflower seeds, dried apples, bananas, pineapple, cherries, apricots, cranberries, and raisins. Unsalted nuts may be added as well if nut allergies are not an issue. This might be the time to try ingredients that you have not tried before. Each person can make his own portion. Measuring spoons can be used; a math lesson could be incorporated.