weathering and erosion STEM Activity for 2nd Grade: Build a sandcastle

Maybe it’s because it’s summer here right now.  Maybe it’s because I haven’t been to the beach in five years.  Or maybe it’s because the kid in me just loves sandcastles.

No matter what the reason, I knew this sandcastle erosion stem activity had to be a part of our landforms unit as soon as I discovered this book by Robert Munsch during my research!

Book: The Sandcastle Contest, by Robert Munsch

Here’s a closer look into our sandcastle erosion STEM activity and challenge for 2nd graders!

Sandcastle erosion STEM activity pin image

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What’s the Problem?

We start by reading The Tide Is Coming In.  This is a simple book with great vocabulary and frames the sandcastle problem perfectly!  The ending is very open ended and leaves a good opportunity for students to hypothesize about what happened to the sandcastle!

Then, I read the scenario on our problem slide we use for our STEM projects and challenges.

problem slide for erosion STEM challenge

We brainstorm ideas within our partners or groups for how to solve Pat’s problem.  Then, it’s time to make a plan!

Planning the Solution

During the planning phase, we work to talk out our solution.  What will it look like? Why do you think it will work?  How will you build it?  Will there be any problems with it?  

Our guiding questions are on our plan slide along with pictures of materials to spark their thinking and ideas.

Once they have talked through their plan, they come get the planning page.  Here they will write down how their plan will protect the sandcastle.  They will list out the materials they need and sketch a picture of their solution.

planning a way to protect the sandcastle from erosion

NOTE: I tried this out with my almost 6 year old, so his answers are obviously simpler than most second grade answers or written responses would be! 🙂

Build the Solution

Earlier in the landforms unit, we explored weathering and erosion with sand and water. But this sandcastle erosion stem activity is all about engineering a strong sandcastle to minimize erosion! So the goals are totally different!

On the second day of this Sandcastle STEM Challenge, students will collect the materials they need and begin building their solution.

To prep for this day, you will want to put a “sandcastle” (a cup of sand) in a foil pan with some sand around it.  Students will be building their solution in relation to the sandcastle inside their foil pan.

materials for the erosion stem activity

While they are building, you will need to actively walk around and continue asking the planning questions to keep them on track and focused on solving the problem.

I would definitely recommend setting a timer for this to keep them focused and to make sure too much instruction time isn’t lost here.

kid example of sandcastle protection

Share and Publish

The third day is all about sharing their solution and testing them out to see if they work.  Because the solutions are all in foil pans, students can easily bring their pan in front of the class and talk through their solution.  The share slide gives the questions students will answer during their presentation: How does your plan protect Pat’s sandcastle?  How did you build it? Does your plan work?  

When it’s time for the last question, it’s time to test out the solution!  I get a pitcher of water and fill the pan with “ocean water.”  Then, the group sloshes the water to mimic ocean waves.  They must slosh it 10 times.  After 10 times, they stop and we observe to see if their solution worked and talk about why it did or didn’t work.

causing waves to mimic erosion to test our sandcastle protection
effects of erosion on our sandcastle

During our writing time, we publish our solution and reflect on how well our solution worked, how we could improve it and by drawing our final solution.

sandcastle STEM publishing

This Erosion STEM activity and challenge can be found separately, or with more landform activities in this Next Gen Landforms unit.

sandcastle STEM challenge TpT cover image
2nd grade landforms unit TpT cover image