THE MIND BEHIND THE RUBIK'S CUBE CELEBRATES A LASTING PUZZLE

If you've ever had trouble solving a Rubik's Cube, a good piece of advice is to break it down into steps. It's worth a shot: That advice is from the man who invented it.

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"Problem solving is a very basic activity of the human mind and if a problem is complex you need to divide the problem into smaller elements," says Ernő Rubik, who invented the cube in 1974.

Rubik has seen his color-matching puzzle go from a classroom teaching tool in Cold War-era Hungary to a worldwide phenomenon with over 450 million cubes sold and a mini-empire of related toys.

"For me, the cube represents what freedom means. Freedom is never endless," he said during a recent visit to New York. "It lets you do what is necessary to achieve your goal." The original 3x3 Rubik's has more than 43 quintillion that's more than 43,000,000,000,000,000,000 possible configurations, but the principles behind the cube have been refashioned for 2x2, 4x4 and 5x5 cubes, a board game called Rubik's Race, a pyramid, a tower and a Christmas tree, among others.