Tuesday, 3 September 2013

Geodesic Structures with Marshmallows

On Tuesday afternoons a good friend and I swap a couple of children - so she takes Eldest to Science Club with her 11year old, Eldest's best friend, while her 6 year old daughter (Little P) stays with me and my younger two.  The little ones and I had a chat and decided that as the big boys we having a Science Club, why shouldn't we?!  So this afternoon we had fun making geodesic structures out of mini-marshmallows and cocktail sticks...

We looked at some pictures on the web of the bio-domes at the Eden Project, and Spaceship Earth at the Epcot Centre in Florida, and talked about which shapes we could see making up the domes...

Then we got the cocktail sticks and mini marshmallows out (and agreed that everyone could eat a couple of marshmallows, but then not to eat any more until we had finished constructing with them).

First we had a go at making simple 2D shapes, sticking the ends of the cocktail sticks into the mini marshmallows...

Then we tried making the basic shapes into 3D ones... it was fun but quite fiddly, the marshmallows wouldn't take too much squishing,which one of the children was prone to do (if I did this again with little ones I might try maybe gumdrop-type sweets as they would hold their shape better, or drinking straws and full-size marshmallows)  The tiddlers did well - Middle in particular enjoyed the experiment.


Mummy couldn't resist having a play at making a large pyramid... and of course a dome...

Of course, there was plenty of experimenting too (not to mention covert marshmallow-munching)...

Then the children evaluated our experimenting...

Best bit about the experiment: eating the marshmallow kebabs.
Worst bit about the experiment: when the marshmallows got too squishy.
Strength of the structures: They stayed up under (reasonable) pressure and wiggling.
Reason for domes like Eden Project and Epcot being built that way: triangles are the strongest shape

After all the equipment had been cleared away (eaten), it even led to a short philosophical discussion...
Little P: "I wish the whole world was made of marshmallows"
Middle: "But then we'd be extinct because there would be no air to breathe"
Little P (undaunted): "well everyone would be extinct except me then"
Life lesson for Middle - you can't argue with female logic ;)


  1. Fabulous! J & I did some of this last year, but were rather short on the cocktail sticks, so I'm sure it's something we'll be doing again. Gumdrops (American Hard Gums) are meant to be pretty good for this too, and then you can use them to make molecule models!
    R x

    1. Thanks Rachel! I must admit I did think about molecules too... was even considering a double helix - but think I might have to save that for Eldest ;)