Saturday, December 17, 2011
What did you say about elephants?
I introduced a brand new engineering problem to my preschoolers recently, and it was a big, big hit with all of us! Our book was
Twenty One Elephants by April Jones Prince which tells the true story of the parade of elephants that marched across the Brooklyn Bridge when it was newly built, to prove its safety and strength.
As usual with my engineering lessons, I only read part of the book at first. Here, I read up until the point where the elephants went on the bridge...then we predicted whether the bridge would remain standing with 21 elephants on it. Two-thirds of my class predicted the bridge would fall; everyone else didn't know what to think. The children simply couldn't imagine that any bridge could support so many elephants. Obviously, 21 elephants was a lot! We counted slowly and aloud to 21. We played "London Bridge is Falling Down." After many laughs during this fun game, it was time to begin our engineering. The children were gripped.
For our engineering problem, we decided to build a bridge out of recyclables that was strong enough to support many elephants. We created bridges throughout the classroom, suspended between two chairs. We tested the bridges by standing five toy elephants on them.
There were so many unexpected gifts from this project.
It proved a fantastic opportunity to teach teamwork!
Several children jumped into the engineering and industriously worked alone, but the frequent result was that their bridges failed.
The children soon realized - "organically," [not dictated by me, but from the situation at hand] - that working in small groups on one bridge was the most successful approach. This way, while one student held up the bridge (between two chairs), others could add supports and/or tape to reinforce the structure. The children offered supportive ideas to one another, often scaffolding off one another’s suggestions.
Several children were so excited by the bridge-building that they worked on more than one team to create a bridge. I must admit it was particularly exciting that these were girls in the class - doesn't our world need more persevering, determined female minds like Sukey, Salma, and Eleanor?
Now, of course, this engineering problem didn't whet everyone's appetite. I had several students build just for a moment and then take off, not wanting to test their bridges. I entreated one young girl to revisit her bridge, with the comment/question - "How might you make it longer?" She looked at me puzzled. I continued, "Look - is it a problem that your bridge is so short? See, does it reach from one chair to another? " to which she quickly replied, "Oh, Ms. Ingram, they will jump!!" and she raced off to play dress ups. Well, perhaps engineering will delight her another day. We are not all in the same place at the same time.
Another unexpected gift of this engineering effort has been the children's continued thinking about bridges. Many of the children are building block bridges now, racing cars over them. Some are drawing sketches of bridges. We have enjoyed the fanciful folktale The Three Billy Goats Gruff, which caused us to think about bridges in a whole new way! This next week, before our winter break, we hope to walk around the neighborhood in the direction of a bridge, to see the bridge from afar. What do we see? How is it supported? What is it made out of? Why does it work so well? There are lots of questions on our minds, now that we have seen how difficult it is to create a successful bridge.
*One last note - I wish I could share all the photos of the children engaged and excited by this engineering challenge - unfortunately, I have yet to hand out photo waivers to my families, so that their children's pictures might be published here in my blog. You'll just have to imagine! But, I've included a few "sanitized" photos of our fun, to give you a visual of the children's work.