So, mystery build… What are you thinking of?
What would happen if you gave groups of kids the same building materials, but then told each team to build something different? How cool would it be to see how they used the materials for several different structures?
This is an idea that I have been mulling over for quite some time. I wanted to do something that would have each group building something different. So, I did try this- with mixed results. The original challenge was that each group would use the exact same supplies, but each would build a different structure. This ended up being rather wasteful since some of the materials were not needed for every task (and kids will try to use them anyway!) So, I re-thought it and came up with a brand new and amazing plan! Take a look!

I call it a Mystery Build! Here’s the premise of this one: Each group will receive a task card describing what will be built along with the rules for each task. Then each group gets a price list of the materials that are available. They must decide exactly what they need and stay within a budget. My third graders LOVED THIS!
First, they received their task cards!
This one is hand written because this was a test class! Later, I made these fancier!

Next, they filled out their price list.
Of course, they had to be mindful of the budget and they could get more materials- only if they still had money left!
Then they started building whatever their task card said to build. Just take a look at this deliciousness!
Rocking Chair
This task was to build a rocking chair that would actually rock. It also had to hold weights!
This was really challenging. The rockers in the photo are made of pipe cleaners ad they are more decorative than functional.
The chair, however, held a cup full of pennies!
Rocket Ship
This task was to build a rocket. It had to resemble a rocket. This team spent a lot of time decorating their rocket ship! Look at that little flag!
TIP: Whenever we try a challenge that involves decorating a structure I get out my scrap box. Students can use paper from the box for making things like the flag, but not for parts of the actual structure.
Marble Runs
This task was to build a small marble run. So, of course, this team made sure to purchase some cardboard tubes!
This task card is the one every group wanted! Marble runs are really fun to build. However, the Mystery Build is a one-day challenge and the run had to be very short to be able to get it finished in one class period.
Build a Bridge
The task for the bridge was that it had to have a span of a specific length so students had to measure that span. The bridge was also tested with weight.
I am not sure why this bridge in the photo has a cup right in the center!
Build a Tower
This task was to build a tower. It has to be a certain height and resemble a tower.
The success with this tower or any of these tasks is entirely dependent on the materials the students “purchase”. After using their money they have to stick with the design idea and attempt to make it work.
It’s a great learning experience to see that small decisions will influence the outcome!
Swing Set
This was also a popular task card. It turned out to be a little bit tricky to make a swing set that would hold a passenger carrier and keep the passenger on it!
We used Lego man as our passenger and some teams (like this one) resorted to adding a roly-poly of tape to his bottom to hold him on the swing.
This was totally amazing fun and made the kids think SO HARD! Choosing the right materials for their task and staying on a budget was really interesting to watch. In the end, we had presentations during which each group shared their specific task constraints and then showed off the structure.
The materials are a hodge-podge of things I just grabbed from my supplies. You can certainly substitute anything that you have on hand.
Are you ready for the nest news?? This challenge is FREE in my Teachers Pay Teachers store! Just click on any of the images to see the details!
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