The girls came home from signing up for the summer reading program, and announced they had to build bridges. Silly me, I thought they'd need to read books, and was caught off guard. Well, a little off guard, I knew the library had a science theme going this summer, and it's not like we've never built a bridge before.
I sent the girls in to watch The Magic School Bus Under Construction, and then sat back to see what they would come up with on their own. The younger girls (ages 8 and 9) opted for a toothpick and marshmallow construction.
They used triangles for extra strength in their design. They learned quickly, that the squishy marshmallows allowed the toothpicks to move, and come apart. A problem they attempted to solve by reinforcing the connections with clear tape - a lot of clear tape - nearly an entire roll of tape.
Then, they discovered another problem. They had wanted to test their bridge with a couple of Lego cars, but they had forgotten to allow a high enough clearance on their bridge.
Finally, they decided to test the bridge with a Hot Wheel. The bridge held, but even with the tape, was not very stable. We all agreed it was not the sort of bridge we'd want to be stuck on in a traffic jam, but it might do for a quick river crossing in an emergency.
A (age 13) had some sort of suspension bridge in mind, but decided it was too much work, and modified it to a simple rope bridge, along the way. She used Dixie cups with toothpicks stuck in the top...
...to support straw pieces tied with dental floss ropes...
...with a straw "bar" threaded between them. There was no pulley system, so the Lego man would have to lean across the bar, and pull himself down the ropes by hand.
While the girls were busy engineering, I did a little Googling, and found a simple craft stick bridge idea from Nicola at My Little Explorer, for us to try together. Nicola's bridge was made by gluing jumbo craft sticks to parallel strips of ribbon.
We opted for masking tape...
...under...
...and over our craft sticks...
...keeping them secure, and covering the sticky side of the loose ends of tape, so they could be used like ribbons...
...for tying up both ends of the bridge. The bridge was sturdy, but without side rails, would be risky on a windy day. It gave me flashbacks of crossing the Royal Gorge Bridge as a child, except that one has side rails.
What do you think? If you were a Lego man which bridge would you choose to cross?
Quentin and I vote for the bottom one. The lack of sides on the middle one seems a bit scary and the zipline one, well, we have fallen off them, too. What fun!
ReplyDeleteLove this idea and that your kids worked in small groups and independently and came up with different approaches!
ReplyDeleteThese are great bridges. I think I like the top one! :)
ReplyDeleteWow! Now that's what learning's all about!
ReplyDeleteThey all came out great. I think the middle one is for me.
ReplyDeleteBlessings, Dawn
I'd like to try the zip line, if I was a Lego man you know. :)
ReplyDeleteOur Lego people would be happy to use your bridges. Looks like a lot of fun.
ReplyDeleteIf I were the Lego man, I'd go for the suspension bridge. :-) But being sensible, I'd go for the last bridge. Side reels would be a good addition though. :-)
ReplyDeleteAnother vote for the zipline here! What great learning. I especially admire your younger girls' patience - it must have taken them ages to tape all those marshmallow joints together!
ReplyDeleteGumdrops work very well. I hadn't tried marshmallows before, but have taught with the gumdrops many times.
ReplyDeleteI've been sharing all your ideas with my children. I just love the learning that goes on in your house. I don't think we will ever be complete unschoolers, but you make 'almost unschooling' very tempting!
ReplyDeleteAnnette - Funny enough, they asked for gumdrops to start with - but we didn't have any on hand, so they went with marshmallows instead.
ReplyDeleteThese are fantastic! I like the zipline, assuming I can be guaranteed to not fall off.
ReplyDeleteI think the last bridge looks the safest, but I like the idea of eating the marshmallow bridge when it's no longer needed!
ReplyDeleteWe made a bridge when we learned about Xerxes, and the kids had so much fun with it.
ReplyDeleteNow, I'm thinking challenging them to make a bridge for a Lego car would be really fun.
The thought of crossing any of those scares me to pieces because I'm scared of heights.