NEW YORK (AP) — 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 made it. Ernő Rubik invented the cube in 1974 and has seen his color-matching puzzle go from a classroom teaching tool in Hungary to a worldwide phenomenon with over 450 million cubes sold and a mini-empire of related toys. The latest brain-teaser is called the Phantom, which takes the 3×3 original cube and adds a memory test: Using thermochromic technology, the tiles revert to black unless the heat of the user’s hand keeps them visible.