Design Challenge: Inflate a Balloon

What You Need:

• Balloons
• Empty water bottles
• Stopwatch
• Pen and paper for taking notes

Materials you can give your child for the mixture that inflates the balloon (not all of these will necessarily be successful):

• Vinegar
• Sugar
• Baking soda
• Salt
• Mentos
• Lemon juice
• Soda, such as Diet Coke
• Any other household items/liquids

What You Do:

1. First, explain the challenge to your child and ensure that they fully understand it. Explain that they're supposed to test out the different materials you're giving them to find a mixture that inflates a balloon in the shortest amount of time. Tell your child that not all of the materials will necessarily work, but they can try out different combinations until they find one that does.
   • Since the goal of this challenge is to find a mixture that inflates a balloon in the shortest amount of time, your child will need to try out several different combinations and compare their effectiveness.
2. Ask your child the following questions so that they start thinking about the requirements for inflating a balloon:
   1. What are some things that you know can inflate a balloon? (Example: helium.)
   2. Why do you think these sources are able to inflate a balloon? What do they produce that inflates the balloon? (Answer: sources that inflate a balloon produce gas. Sometimes the gas that's produced is helium, and sometimes it's carbon dioxide, depending on what exactly is inflating the balloon.)
3. After your child understands the prompt of this challenge, allow them to begin brainstorming different mixtures that they can create to inflate the balloon. Show them the materials so they know what they're working with, but don't let them start making anything yet. Make sure that they're taking note of their ideas on a piece of paper so that they can refer back to them later.
4. After your child has finished coming up with ideas, ask them to choose the one they think will work best. Make sure they are prioritizing the function of the mixture and reiterate its purpose (to inflate the balloon as quickly as possible).
   • This is an important step in the design thinking process because it teaches your child to prioritize the effectiveness of their prototype (design) over their personal preferences and prevents them from getting emotionally attached to their ideas.
5. Now, your child can begin creating the solution they chose in the previous step! Give them all the materials and allow them to start mixing. We recommend that they create the mixture inside a water bottle and quickly cover it with a balloon to see if it inflates.
6. Your child should be "testing" their mixtures as they create them since the ingredients may react quickly. After making their mixtures, ask your child to quickly place a balloon over the mouth of the water bottle. You can help out your child by using a stopwatch to observe how long it takes for the balloon to inflate (if it does, in fact, inflate). Then, have your child record on a piece of paper whether or not the solution successfully inflated the balloon and how long it took to do so.
7. In order to reflect, ask your child some of the following questions after creating their first mixture:
   1. Why do you think this solution was successful? Or, why do you think the solution you created didn't work?
   2. What is something you need to create in order to inflate a balloon? (Answer: gas.)
   3. Do you have any other ideas that you think will work better?
8. Regardless of whether or not your child's first mixture was successful, encourage them to repeat this process a few more times. This way, they can compare several different mixtures and determine which one is fastest at inflating a balloon.
   • If your child has no success after several attempts and is beginning to feel discouraged, you could encourage them to try mixing baking soda and vinegar. This is a combination that should successfully inflate a balloon.
9. Have your child continue repeating this process as long as they'd like (and until they create the best mixture they can)!