Let's find out about cardboard with Kit and Pup! Kit and Pup are playing with differently shaped cardboard boxes, but whenever they stack the boxes, the tower eventually falls over. What could be going wrong? Through their adventures Kit and Pup find out that cardboard can be folded, can be smooth and can be firm. In the live-action investigation a little scientist tests the strength of cardboard tubes by building a cardboard bridge, and in the material world a mini explorer waves from the mouth of a cardboard tube.