This step takes a little work and practice to figure out. A letter with an apostrophe F denotes a 90 degree counter-clockwise turn. That is the center piece that lies directly in the middle of each side denotes the final colour of that side just like on a 3x3.
This is the same method that Emily used to solve the Rubiks Cube when she was 3 years old.
LAYERS There are three horizontal layers in a 3x3 Rubiks Cube. Mindset is critical - learning to solve the Rubiks Cube is difficult but if you persevere you CAN solve the Rubiks Cube. Unlike the original 3x3 cube the 4x4x has no fixed centre pieces and so it is even harder to solve. In 1980 via businessman Tibor Laczi and Seven Towns founder Tom Kremer.