## Monday, February 24, 2020

### Homeschool Math: Make Geometry Nets with Building Toys

Want a super-fun hands-on geometry and spatial reasoning activity for multiple ages of kids?

Make geometry nets!

Unfortunately, almost all of the geometry net kits and models that you'll see are pre-made to form a specific net, and all the kid gets to do is fold and unfold them.

It's better than nothing, sure, and it's still fun to physically manipulate a model, and to guess what three-dimensional shape a particular net will form, but other than that there's not a lot to do there.

It's definitely not the problem-solving practice and spatial reasoning challenge that a kid gets when tasked to use open-ended building toys to make their own geometry nets.

Like these!

 Forgive the poor quality of these photos. We both have inadequate indoor lighting AND homeschool even when it's gloomy outside!

This nifty little set is Googolplex, a vintage building toy that I checked out of our local university's library.

It's too bad that it's no longer manufactured, because it really is perfect for this project. Each line segment had a hinge attached to it, so that you really could fold the planes together and explore what 3D shape they made.

I mostly made boring basic shapes, but Syd enjoyed the problem-solving involved in creating more interesting shapes and then making them move:

Her spatial reasoning game has always been pretty fly.

If you're interested in even more older kid exploration with polyhedra, check out these projects:

• giant cardboard house. I LOVE this house idea! I should have saved the 753 corrugated cardboard Girl Scout cookie cases that have come through my house so far this year to make this with the kids, and I really had been trying to save all those boxes to upcycle, but I hit the wall on Saturday and had Matt take them to the recycling center. Perhaps next year!
• geodesic dome with straws. I don't usually craft with single-use plastic like this, BUT the kids have it on our ultimate wish list to build ourselves a giant PVC pipe geodesic dome in our backyard. We may have to practice our designs with these!
• gross-motor geometric solids. With this Bernoulli windbags, kids can make larger-than-life geometric solids that are as light as a feather. It's really fun!
• paper polyhedra. These are just models to cut out and assemble, but it's a good gross motor activity, good for memorization, and they're pretty!
• tetrahedron wall art. The STEAM skill here is in using pleasing colors and patterns to make art with different sizes of tetrahedra.
• Zometool geometry. This super sophisticated building toy is perfect for complex geometric structures. The antiprism broke my brain!
Will is taking an online geometry course this year, and so I'm always on the lookout for even more interesting and complex hands-on geometry activities. Let me know in the Comments below if you spy something she or Syd would like!