STEM Storytime: Marshmallow Medieval Warfare

Books and Science–y’all know this is totally my wheelhouse!  I built today’s storytime around an IPC marhsmallow catapult lab I have done in the past and a book of castle poetry–Castles: Old Stone Poems by Rebecca Kai Dotlich.  It’s out of print, so tracking it down might be a challenge.


I spy some future engineers!

In particular, the poem about Bodiam Castle, which I’ve visited, provided a great center to kick off our storytime because it was both crushed by the kind of siege warfare we were about to discuss and from my part of England–East Sussex.  I had 6 different Sussex castle pictures in various states of ruin for us to discuss what happened to them and gauge the kids’ knowledge of medieval war machines.  I introduced a set of trebuchet cards (part of the linked handouts Google Doc) and we discussed simple machines and which simple machines we could see in the trebuchets such as pulleys, levers, screws and gears (use the simple machine cards if this is a new topic to your students).


Plastic cup castle.  One for each group and one on top of a coffee table for an extra challenge, because we noticed all of the castles were built on hills!

I recommend having the students divide up a sheet of blank paper into three parts to design their trebuchet/catapult for the base, frame, and throwing arm.  This will help divide up the work for your group of 2-3 and give you a chance to approve the design before they dig in.  I made sure to remind my groups they were limited to the resources in their engineering kit and to look over the instruction sheet for exact quantities of supplies. I have also supplied some design hints for groups who are struggling or over-ambitious, but I recommend you give them at least 10 min to puzzle for themselves before rushing to you for help.


Sample set-up with engineering kits, card sets and instructions.

It would be easiest to spread this out over 2-3 45 minute classes to give kids time to tweak their designs and constructions, but we crammed it all into one 90 minute-2 hr session. If you are going to try to knock down the solo cup castles, be sure to provide something nice and heavy like a heavy gauge nut for the students to use in lieu of marshmallows.


The kids had a blast and I’ve been asked back to do more STEM activities, so hopefully this is something you can fit into your Makerspace time or partner with a science teacher (4th grade and up) to share a lesson!


My Google Docs cardsets and instructions with castle photos

Based on this physical science lab and this one from Scientific American

Amazon link for Castles: Old Stone Poems

Ruler PDF if you want to get fancy with the X-acto knives and hot glue


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s