My sister's husband was all excited at being able to teach the algorithm to all three of us 7-9 year olds as he was a computer engineer at Cray and a friend had brought them in for him before they went on general sale. He then said 'Now go off and come back when all the sides match - the fastest gets five pounds'.
His two came back with a face each. I came back with a completed one.
He didn't actually specify that five pounds was payable only if we followed the algorithm, he just said it had to be done, so although they were so new that none of us knew to take them apart, I'd figured out they must be attached in the middle somehow and maybe a nice, small yet slight curved teaspoon would help me, at which point the first one popped out and I'd found a solution.
His response was muttering something about two programmers and a sodding mechanical engineer.