Design Challenge: Building a Bridge

What You Need:

• Marshmallows
• Toothpicks
• Two tissue boxes of the same size
• Tape measure or ruler
• Pencil and paper for note-taking
• Optional: a small piece of cardboard (about the size of a playing card)
• Optional: at least 20 pennies (feel free to add more)

What You Do:

1. Explain the design challenge to your child. Tell them they have been asked to design a bridge that connects two tissue boxes that are spaced six inches apart. The bridge should also stand on its own without falling down.
   1. Allow your child to place the tissue boxes six inches apart with a ruler so that they can better visualize the challenge.
2. Next, ask your child to define a bridge and its purpose. If you’d like, feel free to look at pictures of bridges online so that your child can see a variety of designs. Some questions you can ask your child include:
   1. What is the purpose of a bridge? (Potential answer: A bridge is a structure that connects two pieces of land across water. A bridge must be able to carry cars and other objects on it, and it must be able to stand on its own over a body of water.)
   2. What, specifically, is the purpose of your bridge? (Answer: To connect two tissue boxes that are six inches apart and to stand on its own.)
3. Allow your child to ideate. Give them a pencil and a piece of paper, and ask them to brainstorm various designs of bridges they can make using toothpicks and marshmallows.
   1. If your child has a difficult time drawing or writing their ideas, feel free to talk it through with them while you write their ideas down on paper.
4. After your child has finished brainstorming, tell them to choose the design they think will work best. Refer back to their answers from step 2, and ask them to prioritize the purpose of the bridge when choosing a design.
   1. This is an important step of the design thinking process because it teaches your child to prioritize the functionality of their design over their personal preferences. This also prevents them from getting too emotionally attached in case their design doesn’t work.
5. Now, for the fun part: prototyping, or building! Give your child the marshmallows and toothpicks, and let them begin making their bridge.
   1. Allow your child to work independently as much as possible, but be sure to help out wherever is needed.
6. Finally, it’s time to test your child’s prototype. Place the tissue boxes six inches apart and place the bridge on top. Ask your child the following questions while they test out their bridge:
   1. Does the bridge you created stand on its own without falling?
   2. Does the bridge connect the two tissue boxes?
7. If your child’s bridge is unsuccessful in any way, make sure that they aren’t discouraged. Frame their failure as an opportunity to try again, and help identify what parts of their design they need to improve. Take your child back to the start of the design thinking process, and repeat these steps until they have created a bridge they are proud of!
   1. If your child’s bridge is successful, try placing a piece of cardboard on top of the bridge and add pennies to it until the bridge fails. Then, challenge your child to build a new design that can hold more pennies than their previous design.