The purpose of this activity is to invent and build with cardboard. 1. Think of something to build out of cardboard or recycled materials: a hamster maze, a game, a dollhouse, etc. 2. Design it. 3. Gather your materials. 4. Construct your design. Ask a parent to help with cutting. 5. Take 's of your plans, the building, and your finished project. 6. a summary of your cardboard masterpiece.