Rubik’s Cube – Orienting the Last Layer Corners

    Published: 06-16-2009
    Views: 178,589
    Rubik’s Cube expert Bob Burton demonstrates how to orient the last layer corners of a Rubik’s cube.

    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.
    I am Bob Burton, Rubik's Cube Expert, and I am teaching you how to solve a Rubik's Cube. At this point we now have the first two layers solved and the last layer edges oriented. The next step is to orient the corners of the Rubik's cube. To do this, we want to look for a solved corner, a corner where the yellow stickers are already facing up. We also want the other three positions to not be yellow stickers. If we have this, we put the yellow sticker with the correct corner in the front left position. Then using the right and top layers of the Rubik's cube, we move the right layer up, the top layer to the left, the right layer down, the top layer to the left again, the right layer up, the top layer twice, and the right layer down. This completely solves the yellow face. Sometimes we get other positions where we don't have any yellow stickers, or it might have two yellow stickers. If we have this we want to look for a way that we can do the same move that we just did, and end up with one correct yellow sticker. This is always possible. Looking in this case, it helps to know what the algorithm we just did does. It keeps the correct corner the same, and it rotates the other three corners of the Rubik's cube clockwise. So, whatever sticker is on top would move clockwise to the side, and any sticker that would move clockwise to be up to the top will move to the top. If we look at this particular case, if we have this one correct, we look at what happened to the other three. This one move up, which means that will have a yellow sticker to the top here. This one, when we move this corner clockwise, this yellow sticker stays to the side. This yellow sticker moves to the top, that means that we will have yellow stickers in the two corners here. This is no good because we only want one yellow sticker. If we move the top clockwise, we check again. This corner will stay the same. This corner, the yellow sticker will move to just back here, when we move the piece clockwise. This one move to the top and this one will stay to the side. That means we will end up with one correct yellow sticker. So, we will do the algorithm; right side up, top to the left, right side down, top to the left, right side up, top side twice, right side down. Now, we have the yellow correct sticker already in the front left. We could do the algorithm we know; up, left, down, left, up, top twice, down. Sometimes we may need to do this twice, but that's okay, as long as we remember what to do in that case, always be able to solve the yellow face of the Rubik's cube. Now that we have the yellow face solved, we move on to solving the edges of the Rubik's cube puzzle completely.