How to Build a Bridge That Holds Weight

Learn the engineering secrets of bridge building by constructing a sturdy structure out of everyday craft supplies.

1. Design your span. Place your two chairs about 10 inches apart. Your bridge needs to reach across this gap. Lay two craft sticks down to see how they span the distance.
2. Strengthen your beams. A single stick might bend. Try taping three sticks together side-by-side to create a wider, stronger beam. Repeat this to make two or three strong beams.
3. Add a support structure. Triangles are the strongest shape in engineering. Try taping sticks together in a zig-zag pattern between your beams to create a truss, which helps distribute weight.
4. Test your bridge. Carefully place your bridge across the gap between the chairs. Slowly add one coin or small item at a time to the center of the bridge. Ask a grown-up to help you record how many items it holds before it bends or falls.