Engineering challenges are a great way to open the world of Engineering to elementary aged students. In my engineering challenges class (and to be honest, all of my afterschool classes on Bainbridge Island) I love to introduce the ideas of trying again, growth mindset, editing ideas, group work…the list is long.
In my engineering challenges afterschool class I like to mix things up from session to session (and even between sessions). I found this paper triangles project online and added a simple, but devilish, spin – students could only build with the triangle pieces. There were no flat pieces in sight. To make this engineering challenge even more challenging I made sure to score my posterboards at 1-inch increments and cut them 1 inch wide. This prevented different sizes of triangles or the ability to stack larger pieces on smaller pieces. Supplies were super simple, I got all of mine at the dollar store. One set of the supplies lasted me for 40 students and took about 1 hour to prep.
Poster board (I only needed 3 sheets from the dollar store)
Oreos and Glutinos (Oreos are pretty alergen free, however I have the Glutinos for gluten free students)
1. Prep your materials
This step mainly involves creating the 3inch by 1inch slips of paper that are scored into thirds (every 1 inch). These slips of paper will fold into the triangle and be taped to stay that way by students. Make sure to have 15 pieces of the posterboard slips for each student or group that will be working.
2. Setup the challenge
I like doing this project in two pieces. I first ask students to spend 5-10 minutes exploring how they can build the tallest tower possible with their 15 triangles. Each triangle must have one face of it either resting on another triangle or on the table surface (ie you can’t stack 15 triangles edge to edge). This helps students see how the triangles can fit together, and what stability issues they face when building tall. They will use what they learn in this part of the challenge for the cookie challenge.
Once kids have had enough time to build tall towers, I ask them to build strong towers. I give them the initial constraints of 15 triangles and the requirement that a triangle face is either on the table surface or in contact with another triangle surface, along with a new constraint. Their tower must be a minimum of three ‘stories high’. I measure the stories as layers of triangles.
3. Test, modify, edit, retest
Kids can test the strength of their towers by stacking Oreo cookies on top of the third layer of triangles. How many Oreo cookies can they stack? I allow my students to ‘win’ an Oreo if their tower effectively holds up an Oreo. This holds true for up to three Oreos, assuming their tower can hold all three Oreos without falling down. The catch, however, is they can’t eat any Oreos until they have finished their project. That is, they can’t find success with one Oreo, eat it, and go back to testing for two Oreos. This keeps kids motivated and on task, as well as helps me make sure they don’t eat a whole sleeve! If a student or team finds no success I let them have an Oreo at the end of class for their efforts. I also give an extra Oreo to the winning student – the current record for Oreos help with only 15 triangles three layers up is a whopping 7!
Ask students to talk about anything they noticed that was surprising. Maybe they discovered certain surfaces were beneficial, maybe they discovered you could take out certain triangles after like Jenga – giving time to recap allows them to process what they learned.