Note: While I call these Valentine catapults because my students used seasonal candy as projectiles, this project can be done any time of year with any projectile of your choosing.
One of the most exciting trends I've seen in schools is the rise in STEM (Science, Technology, Engineering, Mathematics) education. Give any child a bucket of LEGOS or even a box of plain wooden blocks and you will see that they are natural-born engineers. Taking a student's natural curiosity about how things fit together and combining it with scientific principles and mathematics is the absolute best way I have found to engage my students at high levels. Tell your students they are going to become "engineers" for the day and I guarantee you will see eyes and smiles widen, while young brains begin teeming with ideas.
Recently I have started doing monthly STEM challenges with my students — one day a month when we dedicate our time and resources to create something with a specific purpose. Students have built containers to slow down the melting process of a snowball and they've designed escape-proof labyrinths for their crayfish with only 100 blocks. This past week, my students learned a great deal about force, motion, and structure as they worked in teams of three to meet my challenge of building a catapult that could launch a piece of Valentine candy further than any of the other catapults in the room. This week I'm happy to share with you my latest STEM challenge so you can give it a try in your classroom.
The biggest challenge behind my STEM challenges is that I give the students very little information about what they are going to do ahead of time. While they know there will be a challenging design task presented, they have no idea what it is, or what it will involve until it's unveiled during our morning meeting.
To kick-off our catapult challenge, I gathered students on the carpet and asked if anyone had ever heard of a catapult. While most children had blank stares, one boy was eager to share what he knew. He provided a pretty accurate description of a catapult's function, although I cut him off when he said they could also be used to fling cows and that's where it got it's name — the cow-ta-pult. Seriously.
Next, I showed the students a short National Geographic video about an annual catapult competition that launches pumpkins. Once students had the idea, I pulled up a PowerPoint and the challenge was underway.
Click on the image above to download my PowerPoint for your students
We briefly reviewed what we knew about how forces are a push or a pull that can move objects, and how simple machines help us do work. Students were given the sheets that outlined the challenge. They grabbed their iPads and a laptop and got started.
First, students selected their own teams for the challenge. They used a paw print magnet with their name written on it, and the only parameter was that every member of the team had to have a different colored paw. Of course I put a little thought into whose name I had written on each color the day before in order to allow student choice while allowing me to mix the groups and student personalities a bit.
Students answered questions that allowed them to understand what they were building and how it works. My third graders used Google and Siri to search for answers to the initial questions. They had 15 minutes for this portion.
Click on the image at left to download a printable packet for your classroom.
Students had 20 minutes to research a variety of catapult designs and decide what their catapult would look like and what materials they needed. They quickly found how-to videos in their web searches that they watched to help determine what type of catapult they wanted to design.
The materials (and limits) each team was allowed to use included:
rubber bands (6 or fewer)
binder clip (1)
plastic cup (1)
3 things on or in your desk
No other materials allowed
Students gathered their materials, which included a small plastic bag filled with assorted Valentine candies, and returned to their stations. Once I said, "Start designing!" the teams had 30 minutes to complete their design.
After the initial catapults were constructed, students took to the hallway to test them. They tried different projectiles that included small and large candy conversation hearts; gummy hearts; Sweetart hearts; and large, sugar-coated marshmallow hearts.
After each launch, students collected data to help them notice patterns and make changes in their design. They quickly learned that the weight and mass of the objects launched made a difference. They all loved the large marshmallow, but no one could get it to launch further than 12 inches while some of the smaller candies sailed over 20 feet.
For safety, there was a very strict rule making sure the projectiles were never launched when anyone, even a teammate, was in front of the projectile.
After lunch we moved our catapults to the large group instruction room (our former library) for the final launch so each team could show off what they had built.
After a few practice launches, each team launched their Valentine candy twice, while all the other students collected data on what type of projectile was used and how far each piece launched. My students all showed great sportsmanship and camaraderie, cheering on each team and complimenting each teams efforts.
Afterwards, we discussed what the top three catapults had in common and students noticed a few similarities such as 45-degree angles on the fulcrums. Students worked with their team in writing conclusions.
The three designs that launched their candy the furthest are shown above. Interestingly, each one used a different projectile so students concluded the design was the most important factor.
Just when they thought they were done, I told my students there would be a new challenge. This time instead of designing for distance, they needed to build a catapult that could be accurate. Their new goal was to use their catapult to hit a target that was 36 inches away.
In order to learn more about the how a catapult's launch angle impacts distance, I told my student they would have ten minutes to try out a game that used a type of catapult. They were more than excited to be able to download Angry Birds on their iPads.
After their 10-minute investigations, students had 20 minutes to re-design, test and modify their catapult so it could launch a piece of candy with accuracy in mind.
Students learned that a goal of accuracy required less force and a lower angle on the fulcrum.
Perhaps the best part at the end of the day was that many students begged to take home materials to make catapults and show their parents what had learned.
If a high level of engagement is the path to learning at higher levels, then I believe STEM education just may be the best route to take. They have a whole new idea of what engineers do and they are always eager to stretch their thinking to create a working design.
For more STEM ideas see:
"Building Teamwork and Bridges: A STEM Icebreaker" by Alycia Zimmerman
"Taking STEM Education to the Next Level" by Meghan Everette
"Minute to Win It in Your Classroom" by Brian Smith