Who can build the strongest bridge?
Description
Bridge building is a popular classroom activity in science classrooms. In this example a competition is held to see which group can build the strongest bridge. Normally however this activity is not used to its full potential, with teachers moving quickly on to a new topic once bridge building has been completed. This is a shame because the bridge building can be used as a springboard to teaching the principles behind bridge building.
Materials
� Plastic drinking straws
� Paper clips
Procedure
1. A Design Goal; Introduce the lesson by showing the class pictures of bridges. Ask them where the closest bridges are to the school. Ask them if they know of different types of bridges. Which ones do they think are strongest? Why? Introduce the competition to the students: Which group can make the strongest bridge?
2. Planning: Tell the students to work in groups. The bridges will be made from plastic drinking straws and paper clips. The use of glue, string, or paper is not allowed. Ask each group to make some designs for possible bridges.
3. Ask each group to decide which of their bridge designs is the best, and then to write down their reasons why they think this. This will be their design proposal.
4. Building and testing: Each group can now make their design. They can then test it to see how well it holds weights, and then think of ways in which to make it stronger.
5. Evaluation and Redesign: Once they have finished their initial design the group should record their thoughts about how well it worked. New designs should be made, and then new bridges made.
6. At the end of the lessons, the teacher should test each bridge by placing small weights on it. The bridge that holds the most weight before crashing is the winner!
7. Students should record the design process in a special portfolio which includes their initial designs, the design they decided to make, the changes they made to it, and what there final bridge looked like.
This activity will probably take more than one lesson to complete. Bridges can be constructed from a variety of materials such as balsa wood, toothpicks and glue, or simply folded paper and glue. The activity should be used as an introduction to bridges and bridge building. The lesson can be continued by teaching about different designs of bridges, how bridges work, and famous bridges around the world.
Lesson idea taken from Teaching Inquiry-based Science by Mark Walker.