I have an young inventor and builder in my house. He loved tearing up cardboard and making things - mostly space to play in. We had the worlds largest indoor spaceship in our play room forever. Shown are some 90 degree angle cardboard connectors, but I imagine 30, 45 and 60 degree in single and multiple combinations. Just slide the cardboard in and connect.

With leftover cardboard boxes, kids can build and explore as well as get a simple but powerful understanding of spacial geometry (yeah it's simple - we are talking kids).

We used duct tape , hot glue and grommets, but these were not reusable and made the constructions really hard to take apart (took me hours to get that spaceship out). Plus the glue was hot and smelled bad. But now we has a easier way.

I imagine sets of 32, 64, and 128 that would come with multicolored cardboard connector parts and possibly some examples. I could imagine the website forum for the best built cardboard thing.

You know you love it and you know the builder inside your kid will as well.

Probably the 6 -12 year old kid would like this. But, the parent is the target so I have three groups:

The overachiever parent that will key into the geometry aspect.

The parent that recognizes that their child like to make things.

Grandparents

Plus there is also the kid with a gift card.