Here’s a design for a giant cardboard construction.  It is a tricky geometric puzzle requiring lots of problem-solving.  So don’t expect to be done in just an hour or so.  But when complete, it is very impressive. 

A saw is the easiest way to cut the parts out of cardboard, so some folks old enough to use a saw need to be involved.  The template is on the web page and the video illustrates the assembly technique.