huinventors1-2, Exercise 1: Why built, why famous

Model answer:

Rubik built the cube in 1974 as a teaching aid for his students at the Academy of Applied Arts and Crafts in Budapest, to show how an object can move in three-dimensional space while staying whole. It became a puzzle when he scrambled it and found he could not restore it. It became famous because it was a compelling puzzle, because it was taken up by a Hungarian trade organisation and an international toy dealer, and because Ideal Toy launched it widely in 1980. So the reason for building it (teaching) is different from the reason for its success (a puzzle with the right marketing). Details should be checked.