The restoration methods of the second-order Rubik's cube are: up-shun, right-shun, up-reverse, up-reverse, forward-reverse, forward-reverse and forward-reverse. Second-order Rubik's Cube is a relatively simple Rubik's Cube, also known as Pocket Rubik's Cube, Mini Rubik's Cube, Small Rubik's Cube and ice cube. It has only eight corners and no other cubes. The structure is similar to the third-order Rubik's cube, which can be restored by the formula of restoring the third-order Rubik's cube.
The origin of the second-order Rubik's cube
The earliest patent of the second-order Rubik's Cube was applied by Professor rubik Arne on March 29th, 1983/kloc-0. The U.S. patent number is 4378 1 17, which we used to call the second-order Rubik's cube with R structure.
Li of Taiwan Province Company applied for the second-class patent of another structure, the United States patent. No.5,826,871582,6871,we used to call it the second-order Rubik's cube with Dong Xian structure.