This fun, hands-on activity helps students learn about the layers of the Earth's interior. After some background information about the structure of the Earth, students cover balloons with papier-mâché. After the "globes" dry, students cut out wedges from a manila file folder. Next, they paint the globes and wedges to illustrate the interior and the surface of the Earth. Once finished, the models make a great display for the classroom, and enable students to retain their knowledge throughout the year.