Become an engineer and discover how folding and layering paper can make it strong enough to hold a heavy load. You will test different designs to see how many pennies your bridge can support before it collapses!

Tools

• ruler
• pennies (approx. 150 coins)

Materials

• printer paper (8.5 x 11 inch, 3 sheets)
• heavy books (2 books to act as bridge supports)
• small toy figure (1 figure, e.g., 'Norbert')

Safety

• Adult supervision is recommended when handling large amounts of small coins to prevent choking hazards for very young children.

Steps

1. Place two heavy books on a flat surface, leaving a gap of a few inches between them to represent a river.
2. Take one sheet of paper and lay it flat across the gap. Gently place a penny on top to see if it can hold the weight (it likely will not).
3. Redesign the paper by folding each long side of the sheet toward the center to create a reinforced structure.
4. Fold the front edge of the bridge down slightly so you can easily see the pennies as you add them.
5. Place the folded bridge across the books, ensuring it overlaps each book by about one inch.
6. Carefully add pennies one by one to the center of the bridge. Count them aloud until the bridge bends or collapses.
7. Record how many pennies the single-sheet bridge held.
8. Create a second bridge by layering two sheets of paper together and repeating the folding process. Test this bridge with pennies and record the new total.
9. Create a final bridge using three sheets of paper layered together. Test this bridge to see if the strength continues to increase.
10. Once you have built your strongest bridge, carefully place your toy figure on top to see if it can safely cross the river!