Rubik’s Cube – Permuting the Last Layer Corners

Description

Rubik’s Cube expert Bob Burton demonstrates how to permute the last layer corners of a Rubik’s cube.

Expert

Bob Burton

Bob is a math teacher at a high school in New York City. He received his B.A. in mathematics from Rutgers University and is currently pursuing a M.A. in mathematics education from the City College of New York. He also has a great interest in the sciences, especially physics and chemistry. Bob has been solving Rubik's Cubes since 2001 and competed in over twenty official contests all over the world. He has held several world records and national titles for Rubik's puzzles, including the Rubik's Magic and Square-1. At Rutgers University, Bob founded the RU Rubik's Cube Club, which hosted official competitions twice each year, attracting competitors from all over the country in addition to several international competitors. He has also developed several fingertricks for Rubik's Cube algorithms that are used by some of the fastest speedcubers in the world. Bob is also the webmaster for cubewhiz.com, a site designed for speedcubers to learn new tricks and become faster. He currently averages about twenty seconds to solve a Rubik's Cube with a personal best of 13 seconds. He has even solved the puzzle blindfolded in several official competitions. Bob currently lives with his family in Kearny, New Jersey.

Transcript

I am Bob Burton, Rubik's Cube Expert, and I am teaching you how to solve a Rubik's Cube. We are now on our last step, permuting the last layer corners. To do this we look for a set of three pieces that form a corner of a Rubik's cube, where the two edges match the corner piece. We put that in front of us so that were going to rotate cubes starting with the rightmost piece. To do this, we put the right side down, front side clockwise, right side down. We move the back twice, put the right side up, front counterclockwise, right side down, back twice, and right twice. Sometimes we may need to do this twice, since this is also a three cycle. We well do this again; right side down, front side clockwise, right side down, back twice, right side up, front side counterclockwise, right side down, back twice, right twice. We have now solved a Rubik's Cube. There is also one more possible case where sometimes we don't have those three pieces next to each other that we need. If this is the case, we can look at any side of the Rubik's  cube and do that algorithm; right side down, front clockwise, right side down, back twice, right side up, front counterclockwise, right side down, back twice, right twice. We then, again, put the corners, the solved corner, in the front left and do the algorithm we know; down, front, down, back twice, up, fix the front, down, back twice, right twice. You now know how to solve a Rubik's Cube from any state. Now that we know all the steps to solve a Rubik's Cube, let's solve one from start to finish.

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