Sidewalk Chalk Geometric Art

I built a cardboard octagon template to play with math and sidewalk chalk during The School's weekly recess in the park.

I used three pieces of cardboard for this template. The Skil cardboard cutter made quick and easy cuts, though its speed was a little intimidating and young students would need supervision using them. The pieces were glued together with Elmer's glue.

The 3D printed rivets are one of my favorite go-to 3D printed tools. They work best in ABS because they need to be a little flexible. They are optional but do provide a good means to attach the handle. 

I wrapped the edges in masking tape since the glue did not extend to the edges and I wanted something slightly more durable than cardboard for the chalk to come in contact with.

I took the template to recess and drew a couple designs. The template was easy to work with and it was fun to replicate some TurtleArt designs with which I was familiar. 

The students enjoyed playing with the template, too.

 My son had fun with it as well.

I worked on a more complex design at home. Using different color chalk in the shapes created by overlapping shapes brings complexity to the design.

Next, I built a circle template. I used a Home Despot bucket lid as my template and cut it with a box cutter and a new blade. This time I used two pieces of heavy duty cardboard. 

The cardboard was too thick for the rivets to go through both layers, so the washer end of the rivet is sandwiched between the layers. 

I used duct tape to cover the edge and help attach the handle over the rivets.

Using the edge of the sidewalk helped me arrange the first row.

I filled the overlapping shapes with different color chalk. You don't need to draw too hard to create the fill: try not to burn through your chalk by gorilla'ing it into the ground.

People have suggested different materials from MDF to laser cut acrylic and I encourage them to pursue these materials. However, I felt strongly about stopping at cardboard and iterating on details like cardboard heaviness, tapes, and whether the 3D printed rivets were necessary because I wanted this project to scale. Most people do not yet have ready access to laser cutting, while cardboard is nearly ubiquitous. 

@tieandjeans asked what other shapes might be a good "starter kit." Circle, Square, and Triangle, of course, and whatever other polygon tickles your fancy.

Build some templates for yourself and share the shapes you and your students create.


Amy zimmer said…
Super Amazing Coolio! I would have my HS Geom students construct the hexagons and circles on the cardboard using our whiteboard compasses. (Our school doesn't have that cutter thingie or a 3D printer) Still thinking on it, AND I am all over it...Thank you so much for sharing! Especially love elementary (?) and HS having this convo!