"What Do You Beuse?" - Making use of an old cereal box... #toddlercrafts

My little boy recently came over to me and asked

-"what should we "beuse" mom?"
I responded: "what?"
-"you know..you know.. beuse becycle!?!"  Oh of course, what else did I think?  ;)
*smiles* with joy and in love with how he says it.  We then used up an old cereal box and used it for crafting per his suggestion!  We've created so much over the years with boxes and old scraps of this and that.. I needed ideas.  I was able to find something titled "Upcycled Cereal Box Marble Run," and happened to have plenty of marbles and cereal boxes to try it ourselves.

I ended up using two cereal boxes..because once I cut open one, I found two coupons in there that I could use.  Did you know there were coupons in there?  I didn't!

 I poked some holes and twirled my scissors in there until it got to the perfect size for the marbles.  Whatever tape you have in hand will probably work.
 It is pretty easy to make, my son kept saying it was "boring looking" so we painted it as well.
Have you done this before?  Will you try it?  And most importantly, what do you "beuse?"- My son wants to know! ;)