48-Piece Constructagons™ Giant Building Set for Life-Sized Structures

I bought these for my son, who loves to build "forts" and towers. Perhaps I didn't read the product description closely enough, but I was disappointed to see that these are made of cardboard. I fear they won't last long with 3 children at home. My 5 year-old was impressed by the arch and "dog" that I built, but became easily frustrated trying to connect the pieces himself. In fact, it was somewhat challenging for me to build the arch. Time will tell if my son enjoys building with the constructagons. Perhaps the cardboard bricks would have been a more age appropriate bet.