Some Days You're a Cube , Other Days You're a Rectangular Prism!

I wanted to share with you a brainstorm I had the other night at (of all places) Walmart.  Hah hah.  Normally I get my best ideas in the shower, but this was while I was pushing the cart down the aisle, my class in the back of my head (as always...I think all teachers do that, right?) when I had a sudden inspiration.

A little background....we are currently in the midst of our Geometry unit.  Students in second are introduced to 3D figures, and have to not only name a cube, rectangular prism, and sphere, but know vertices, faces, angles, and edges!  My poor lil ones were struggling with all of the above.  So, I had a sudden flash of insight:  marshmallows and toothpicks!  Well, if you're going to have a brainstorm, Walmart WOULD be the place to do it!  So, I grabbed a 250 pack of toothpicks (should have grabbed two) and 2 bags of mini marshmallows.  Pretty cheap project, actually.  Think it cost less than $3.

That evening, I spent most of my time cutting toothpicks in half and constructing my own cube and rectangular prism.  I baggied up the supplies my students would need for the cube and a separate one for the rectangular prism. 

On Tuesday, my kids built their cubes first.  To make the cubes, you need 8 marshmallow ("vertices") and 12 toothpicks (6 cut in half). 

To make the rectangular prisms, you need 8 marshmallows ("vertices") and 4 regular size toothpicks and 8 shorter toothpicks (4 cut in half).

To add to the lesson, we went over what each part of the solid was.  The toothpicks were edges, the marshmallows the vertices, and of course the space on the "inside" of the vertex was the angle.....the only thing we were "missing" were faces, but that was the one concept that my kids had overall really gotten.  (You could probably cut card stock to "fit" in the space for faces if your students weren't sure about it).


Needless to say, it was a hit.  I only really needed one big bag of the mini marshmallows for 21 students, but I used the extra bags as incentive.  The students all had to answer a question about their figures before they got the extra marshmallows to munch on.  Students then placed their "solids" in the baggies to take home and practice building in front of their parents.

It really seemed to help some of my students who were struggling.  Granted, they had been handling shapes in the classroom and we had been attempting to draw (which is very hard for 3D!).....but I think actually "building" it made all the difference!