Sidewalk chalk paint & it’s crazy easy to make! (two muffin tins of paint): cups cornstarch and cups water. Once it is all mixed up, divide it among the 12 muffin cups and add two drops of food coloring to each muffin cup
Weather experiment - take a clear plastic cup and add plain water. Put a small amount of shaving creme on top. Then a few drops of red and yellow food coloring. The food coloring slowly finds it's way down into the water to make ORANGE rain! What fun!