To share with the entire class:

• 5-7 6-foot lengths of foam pipe insulation tubing, cut in half lengthwise per group
• 2 rolls masking tape
• 2 boxes round toothpicks (~20 per group)
• 16 mm marbles (5 per group)

Each group needs:

• container to catch marbles
• flexible tape measure
• scissors and ruler
• 2 different-colored stickers, one marked "P," the other "K"
• Worksheet 1: Reference Diagram
• Worksheet 2: Design and Building Guidelines
• Worksheet 3: Cost and Evaluation Sheet