This is outstanding visual demonstration of a simple test that can be used to show why or how something happens. It is a great opportunity to use the scientific method to hypothesis and make predictions, which can then be evaluated after the experiment has concluded. The activity calls for materials that are readily available around the house, but they can also be easily substituted (i.e. the “balloon” can be any airtight material which can be secured to the top of the container). The resource offers a video and step-by-step directions, making this activity accessible to scholars of all ages. It also has a review portion that explains the science behind the activity.