We got the idea from this from Jerry Slocum and Jack Botermans "New Book of Puzzles". The puzzle dates from the 1930's and we tried to copy the old design nearly identically as pictured in Jerry's book.
The object of the puzzle is to get all 4 sides to add to 555, the height of the Washington Monument! Each of the cubes will rotate on the internal post.
A great challenge for the math inclined as it is VERY difficult. It might make a good class project from middle school to high school.
There are over 262,000 possible permutations of the disks. There are only 9 possible solutions.