The center squares tell you everything. The center squares are on x-y-z axes. Although you can move all the Rubik's pieces around, every center square will *always* be opposite of another *specific* center square. The white Center will always be opposite of the yellow Center. The red Center will always be opposite of the orange Center. The green Center will always be opposite of the blue Center. This is the key to solving Rubik's Cube. The color of the center squares tell you where to put every other piece.
In the photo above, you can see the red, white, and green Centers. Even without looking, you can be certain that on the opposite side of the red Center, will be the orange Center. Opposite of the white Center will be the yellow Center, and opposite of the green Center will be the blue Center.
In the photo above, the white-Center side of the Rubik has one piece that is white and red, and another piece that is white and green. These 2-color pieces I will call by the name Edge pieces. I can tell where I want to put every Edge by simply looking at the Centers. The white-green Edge connects the white and green Centers. The white-red edge connects the white and red Centers.
I solve the Cube one layer at a time, and I start with the white side. I would suggest doing the same, at least until you've done it a couple times, simply because these photos will make more sense and be more helpful.
I'm making one big assumption, which is that you will be able to make a white cross, and get all of the corners of your first-layer into their correct "positions". What I mean by this is shown in the photo above, all the pieces surrounding the white Center are in their correct *positions*. In the photo above, the Corner square closest to you is red, white, and green. The Center colors touching this Corner are also red, white, and green. Because the *three* colors of the corner MATCH the *three* colors of the Center Squares the corner is attached to, the red-white-green corner is in the Correct Position. Because the color of each of the corner tiles does NOT MATCH the color of the Center Square it is touching, the corner is not Oriented correctly. The corner needs to be spun to be solved.
If you have difficulty getting the pieces for the first layer into the correct positions, I would suggest first learning how to solve a 3x3 8 puzzle. The movements you use to solve the 3x3 8 puzzle are the same type of movements you use to put the Rubic pieces into their correct first-layer positions . One resource for learning how to solve a 3x3 8 puzzle is wikihow. An internet search will give other links which will help you learn this. Here's a link to a digital version of an 8 puzzle, if you want to practice it. Shout out to my cousin Rick, who taught me to do the 8-square at grandma and grandpa's house, when I was maybe 6 years old.
"Two roads diverged in a yellow wood," as Robert Frost wrote. If you want a shorter version, which summarizes a more Self-Directed learning method, continue reading below. If you want all the details of my If-Branch explanation, go here.
When I solved the first layer, I first put the Edge pieces in position to make a "cross". This was shown with the white Edges in photo 02. When putting these *Edges* on the first layer, I made sure the colors were oriented correctly. This was also shown in photo 02, with the white/green Edge oriented so that the colors of the Edge matched the colors of the center squares they were next to. Same thing with the white/red Edge in photo 02.
When I solved the first layer, I then put the Corners into their correct "position". If they went to their position with the correct "orientation", that was fine, but it was not necessary. In photo 02, the red-green-white Corner colors did not match the Center colors they were touching. Correcting the orientation was easy to do, with the following algorithm.
Special Announcement!!! All of the algorithms below began with a specific orientation. Part of that orientation was that I was holding the cube so that a specific Center square was facing me, as I began the algorithm. For every algorithm, I KEPT THAT SPECIFIC *Center square* facing me until I finished ALL the turns of the algorithm!!!
The first algorithm I used was the Corner-spinning algorithm. With the Corner-spinning algorithm, I could put the corners of the first-layer into their correct positions, and then spin the Corners to solve the first-layer.
Starting with the green Center facing me, and the white Center facing up, this algorithm spun the top-right corner of the front side, as illustrated in the picture below.
NOTE: Starting with the green Center facing me, and the white Center facing up, this algorithm moved the white tile on the right side, to the upper side. But what if I had wanted to move the tile on the *front* side, to the upper side? This algorithm works for that also. I would've peform the algorithm to move the red tile from the front side, to the right side. Then, I would've simply performed the algorithm *again*, to move the red tile from the right side, to the upper side.
One trick which will help you rotate the correct pieces: for each move of an algorithm, put your fingertips, *or* thumb, over the squares covered by the move-arrow in the algorithm diagram below. With your fingertips, *or* thumb, over the squares covered by the move-arrow, your hand will naturally rotate the correct pieces.
For each move of each algorithm, you will rotate one side 90 degrees. 1/4 of a full circle. There is one exception, and that will be explained in detail in the section Transpose Yellow-Cross Edges.
Which direction do we rotate the pieces? If there is *NOT* an apostrophe after the letter, we rotate the side CLOCKWISE. If there *IS* an apostrophe after the letter, we rotate the side COUNTER-Clockwise. Clockwise or counter-clockwise is defined by imagining that we are looking straight at the side we are rotating. For example, R' means we rotate the Right side of the Cube COUNTER-Clockwise. This is shown in the first turn of the diagram below.
Remember, I started the algorithm with the green Center facing me, and the white Center facing up.
This algorithm changed the Cube from photo 02, to photo 03 below. This algorithm solved the red-white-green corner.
I *CONTINUED HOLDING THE CUBE WITH THE GREEN CENTER FACING ME, AND THE WHITE CENTER ON TOP*, for the rest of these steps, until the White-layer was solved.
From Photo 04, I changed the red-white-blue Corner in the same way. I continued to keep the green Center facing me, and kept the white Center on top, while I rotated the upper-layer until the red-white-blue Corner was in the top-right of the side of the cube facing me. The side with the green Center. I then used the same algorithm and spun the red-white-blue Corner.
The algorithm spun the white-red-blue corner so that the white tile was facing up.
I rotated the top layer so that the center squares of the middle layer matched the colors of the top layer, and the white-layer was solved, as shown in photo 05 below.
!!!Pro Tip!!!: When I solved this first-layer, I *tried* to use the algorithm above *at least* once. I did this because the *LAST STEP* of solving the *WHOLE* Cube involved using the algorithm above. I wanted to practice the algorithm above during the first step. If I messed this algorithm up on the last step of solving the whole Cube, then probably I would have needed to start all over again, back at this first step.
I TURNED THE WHITE SIDE SO IT FACED DOWN. THE BOTTOM LAYER WAS SOLVED, WITH EVERY PIECE MATCHING ITS CENTER-SQUARE COLOR.
Now that the bottom layer was solved, the next step was to solve the middle-layer. Remember, the Center squares told me where to place all the other pieces. In photo 06 above, I wanted to move the orange-blue Edge from the upper-layer, so that it would connect the orange and blue Centers. I held the Cube so that I was looking at the orange Center, with the yellow Center on top, and used the algorithm below to move the orange-blue Edge to the *right*.
The strength of this algorithm was that it moved the orange-blue edge where it belonged, but it *also* kept the bottom-layer solved.
But what if I needed to move the green-red Edge to the *left*, like in photo 07 above? I held the Cube so that the green Center was facing me, with the yellow Center on top, and used the algorithm below to move the green-red Edge to the *left*.
Again, the strength of this algorithm was that it kept the bottom-layer solved.
I only needed these two algorithms to solve the middle-layer. I matched a middle-layer Center color with an upper-layer Edge color. Then I used an algorithm to move the Edge piece, so that the other (top) color of the Edge piece would match the Center square on the left side or the right side.
What if we've moved all the non-yellow Edge pieces from the upper-layer, and there are Edge pieces in the middle-layer that are in the WRONG position? What do we do with the middle-layer green Edge in photo 08 above? The solution is to use one of the two algorithms above, to move a yellow-colored Edge piece from the upper-layer, to the position of the green Edge in the middle-layer. This will *also* move that middle-layer green Edge to the upper-layer. From photo 08 above, we use the move-left algorithm to move the red-yellow Edge to the middle-layer green Edge. We do this to move the green Edge to the upper-layer.
After the green Edge is moved to the upper-layer, we use one of the two algorithms above, in the same way as before, to move the green Edge from the upper-layer, to its correct position in the middle-layer. This will solve both the bottom layer and the middle layer, as shown in photo 09 below.
THE BOTTOM TWO LAYERS ARE SOLVED, WITH EVERY PIECE MATCHING ITS CENTER-SQUARE COLOR.
The next step towards solving the Cube is to make a yellow-cross on the upper-layer. By "yellow-cross on the upper-layer", what I mean is that the yellow Center square is on top, and all four of the Edge pieces have yellow facing up.
For this complete drop-down section, IGNORE all four upper-layer Corners.
>>>Sometimes, when you finish solving the bottom and middle layer, the Cube will have a yellow-cross on the upper-layer, like shown in photo 10 above. Don't worry if the upper-layer Edge colors don't match the Centers of the middle-layer, we'll fix those in the next section, after photo 14. If your Cube already has a yellow-cross on top, skip this section, and JUMP to the instructions under photo 14, Transpose Yellow-Cross Edges. Note that photo 10 and photo 14 are the same picture. Sometimes you will arrive at this step and the Yellow-Cross will already be on the Top layer, but mostly you have to work to put it there.
What you will do now is use one algorithm to change the pattern of the upper-layer from "Yellow-Center-Only", to "Yellow NorthWest", to "Yellow Horizontal Line" to "Yellow-Cross". You want the upper-layer to be a "Yellow-Cross", and how many times you need to use this algorithm is determined by the (random) starting-state of the upper-layer.
Above is the graphical overview of the way this algorithm moves the upper-layer to a Yellow-Cross. How many times you must perform this algorithm is randomly determined by the state the Cube is in when you get to this step.
Pretty rarely, when I'm solving the cube, it doesn't move directly from one of the above pictures, to the next. I've always assumed this was because I had made a mistake, but teaching is one way to learn. While writing this page, I've been questioning this, and now I'm paying more attention to it. I hope to update this soon. Whether this has been my mistake, or it has been caused by a state of the cube, I have to think it will happen occasionally to you. Don't worry about this, because it has never really been a problem with me. I've never paid it much attention in the past, because I simply repeat the steps here with this algorithm, and the cube will fall back into this sequence of progression towards the Yellow-Cross On Top.
You now have a choice. If you want a shorter version, which summarizes a more Self-Directed learning method, continue reading below. If you want all the details of my If-Branch explanation go here.
First off, notice that there are some missing numbers on the photographs. They should all be sequential, but some of the steps are being left out of this version. This is the down and dirty version. I'm giving you a pole, pointing you to the lake, and I'm confident you'll come back with some fish.
What you need to do is look at the yellow layer of your cube, and match it to one of the states in the above overview. You might have to rotate the whole cube to make a vertical line into a horizontal line, or you might have to rotate the whole cube to get to the "backwards L" "northwest" shape in the overview's second picture. Perform the algorithm below, and it should move your cube to the next picture in the overview. Keep repeating the algorithm below until you get a yellow cross on top, and then jump to photo 14.
Put the yellow Center facing up, and pick a Center square to focus on while you perform the algorithm below. Keep that Center square facing you. I've chosen the red Center square, and I will keep that square facing me, while I perform the algorithm below.
Every time, before beginning the algorithm below, make sure the Yellow Squares on the Top Layer match one of the pictures in the overview above. The Yellow Squares on the Top Layer are your first guide, but also, whatever color is facing you from the Center Square of the front side when you start the algorithm, should continue facing you throughout the algorithm.
In the photo above, the bottom two layers are solved, and there is a Yellow-Cross on the upper-layer. Sometimes when you make the Yellow-Cross on the upper-layer, all four of the Yellow Edge-pieces will match the color of the Center squares. If that happens, go straight to the instructions under photo 16.
Sometimes when you make the Yellow-Cross on the upper-layer, all four of the Yellow Edge-pieces will match the color of the Center squares *if* you simply hold the Cube with the Yellow-Cross on the upper-layer, and rotate the upper-layer 90 degrees, or 180 degrees, or 270 degrees. If you can rotate the upper-layer to match all four of the Yellow Edge-pieces to the Center squares, do that, and go straight to the instructions under photo 16.
If you can't get the Edges of the upper-layer to match the color of the Center squares, then rotate the top layer until two of the Edges of the upper-layer *WILL* match the color of the Center squares *IF* you *SWITCH* the Top-Front Edge with the Top-Left Edge. Photo 14 above is an example of this. IF you SWITCH the orange and the blue edges in the top layer, then they will match the Center squares. The algorithm below will do that.
Notice that the algorithm below does something that we haven't done before. The algorithm below includes "2U". This means we are rotating the Upper-layer *twice*. In other words, we are rotating the Upper-layer 180 degrees. 2U rotations are easier, because it doesn't matter *which direction* we make the rotation. If we rotate the Upper-layer 180 degrees in *either* direction, we will get where we want to go. The diagram below illustrates this, with both a green double-arrow, and a red double-arrow. This shows that we can rotate the top layer in *either* direction. (*not* both directions.)
Photo 15 shows the results of the algorithm above. The orange-yellow and blue-yellow Edges have been switched, and they are now in their correct positions. Note again, the algorithm doesn't mess up the bottom two layers, and they are still solved.
What about the other two Edges of the upper-layer? If they are *not* in their correct positions, we place them in the same orientation. We turn the *Whole* Cube so one of the incorrect Top-Edges faces us, and the other incorrect Top-Edge is on the left side. Then we do the same algorithm, to transpose them to their correct positions.
THE BOTTOM TWO LAYERS ARE SOLVED, WITH EVERY PIECE MATCHING ITS CENTER-SQUARE COLOR. THE TOP LAYER HAS A YELLOW-CROSS, AND BOTH COLORS ON EACH YELLOW EDGE-PIECE MATCH THEIR CENTER SQUARES.
You will use the algorithm in this section, 0-3 times, before you can move to Photo 17. How many times you use the algorithm is determined by the (random) state of your Cube when you arrive at Photo 16. Most of the time, you will use this algorithm one or two times.
Now that the Yellow-Cross on the Upper-Layer is solved, look at the Upper Corners to see if they are in their Correct Positions. You just solved the Edge Pieces of the Upper Layer, so rotating the upper layer to put the Upper Corners into their correct position, will mess up the Edge Pieces. You must move the Whole Cube, to determine if you have 1, 4, or 0 Upper-Corners in their Correct Positions.
Also remember, by "Correct Positions", I don't mean that they are solved, but that the *three* colors of the Corner-Piece are the same *three* colors of the Center-Squares that are next to the Corner-Piece. For example, in photo 16, the green-orange-yellow Corner is in the Correct Position, even though the green-orange-yellow Corner is not solved.
>>>Are *all 4* Upper-corners in their Correct Positions? If *all 4* Upper-corners are in their Correct Positions, go directly to the instructions under photo 17.
You now have a choice. If you want a shorter version, which summarizes a more Self-Directed learning method, continue reading below. If you want all the details of my If-Branch explanation go here.
The algorithm in this section can be used to put *all 4* Upper-corners into their Correct Positions. At the end of this algorithm, the top-right Corner will be in the same position, but the other three Upper-Corners will switch positions in the upper layer, in a counterclockwise direction.
If your Cube has *ONE* of the Upper-Corners in its Correct Position, skip to the instructions below the next diagram.
If your Cube has *NONE* of the Upper-Corners in their Correct Position, then keep the yellow Center-Square facing up, and look at one of the center squares, while you perform the algorithm below. It doesn't matter which color Center-Square faces you, *AS LONG AS* you keep the *SAME* Center-Square facing you throughout the algorithm. This algorithm will put one of the Upper-Corners into its Correct Position.
With one Upper-Corner in its Correct Position, hold the cube with the Yellow Center square facing up, and move the Whole Cube so that one correct Upper-Corner is in the top right of the side facing you. Note the color of the Center-Square in the Front Side facing you. Keep that Center-Square facing you until the end of this section.
To perform this algorithm on photo 16, I held the Cube so that the yellow Center-Square faced up.
Because the Cube had only one Upper-Corner which was in its Correct Position, I turned the *Whole Cube* so the green-orange-yellow Corner was in the top right, at the start of the algorithm below.
>>>Are all four of the Upper-layer Corners now in their *correct positions*? If so, go to the directions under photo 17.
If all four of the Upper-layer Corners are *not* in their Correct Positions, perform the same algorithm *again*. Keep the Yellow Center-Square facing up, and the same Center-Square facing you, as you perform the algorithm for what should be the last time.
>>>All four of the Upper-layer Corners should now be in their correct positions. Sometimes, although it is rare, putting the four Upper-layer Corners into their correct positions, will also solve each of those Corners. If that happened, the Cube is solved!
>>>If the four Upper-layer Corners are in their correct positions, but all of those corners are *not* solved, move forward to the directions under photo 17.
>>>If the Cube does *NOT* have the bottom two layers solved, with a yellow cross on top, and every Upper-layer Corner in its *correct position*, you've made a mistake somewhere along the way. You will need to move backward to find the instructions for the state your Cube is in. This might mean you have to go back to Photo 1, but maybe you only have to continue from a previous algorithm - it depends on the state of your Cube.
THE BOTTOM TWO LAYERS ARE SOLVED, WITH EVERY PIECE MATCHING ITS CENTER-SQUARE COLOR. THE TOP LAYER HAS A YELLOW-CROSS, AND BOTH COLORS ON EACH YELLOW EDGE-PIECE MATCH THEIR CENTER SQUARES. EACH OF THE YELLOW CORNERS IS IN ITS CORRECT POSITION.
You now have the Cube solved, except for one or more Corners in the Upper-Layer which need to be spun. So far, we've been able to see the progress being made with every step. First, we saw the bottom-layer solved. Then, we saw the middle-layer solved. Next, we placed the Yellow Cross on the upper layer, and moved the Upper-Layer Corners into their correct positions.
We are now very close to completely solving the Cube, but in this last step, the colors are going to explode in every direction. The cube will appear to be completely messed up, but then, suddenly, it will be completely solved. You have to focus on correcting one Upper-Corner at a time, and remember that the algorithm will solve the rest of the pieces.
In order to help keep this focus, always keep the Yellow Center-Square facing up.
Also, pick one Upper-Corner that you want to spin first, and turn the *Whole Cube* so that corner is in the top-right of the side facing you. With that corner in the top-right, what is the color of the Center-Square of the Front side? Remember the color of that Center-Square. That Center-Square should continue facing you for the rest of the directions.
And don't forget, in addition to keeping that Front Center-Square facing you, for the rest of the directions, *also* keep the Upper Yellow Center-Square facing up.
If you do those two things, the only other thing needed, is to repeat the algorithm that you may have practiced in the very first step, when we were solving the first Layer.
You now have a choice. If you want a shorter version, which summarizes a more Self-Directed learning method, continue reading below. If you want all the details of my If-Branch explanation go here.
There are some missing numbers on the photographs. They should all be sequential, but some of the steps are being left out. This is the short version. You might be someone who configures your voicemail to only allow the shortest amount of time possible, and I'm trying to leave a message that doesn't get cut off.
A similar diagram was shown in The First Layer drop-down section. If I perform the algorithm in this section, with the red center facing me, and the yellow center facing up, I will spin the top-right corner in the direction shown in this picture.
I will walk you through these procedures, starting with the Cube in Photo 17. The first Upper-Corner that I'm going to solve is the red-green-yellow corner which is nearest the viewer.
Be aware that in Photo 18, the *Yellow* side of the red-green-yellow corner is facing to the right-side, and this was clearly shown in Photo 17. Because the *Yellow* side of the red-green-yellow corner is *facing* to the *right*, I will ONLY have to perform the algorithm below ONE TIME to spin the *Yellow* side to the top.
From photo 18 above, I perform the algorithm below. MAKE SURE when you perform the algorithm below, that you COMPLETE EVERY ROTATION. The last D-rotation will NEVER affect the Upper-Layer Corner that you are working on, *BUT* it is needed to bring all the *OTHER LAYERS* back to their solved states. Our guidepost for this whole section is the yellow tile of the Front side's top-right corner. That tile gets moved to its correct position with the 7th move in the diagram below, but you must focus on *also* making the 8th and last move. We have to make every move of the algorithm, EACH TIME, so the algorithm can bring the lower two layers back to their solved state, while we are solving the upper layer.
Now the red-green-yellow Corner is completely solved. I no longer have the bottom-layer or middle-layer solved, but I'm not worried about that. I'm focusing on keeping the Front Red center-square facing me, keeping the Upper Yellow center-square facing up, and solving the Corners in the Upper-Layer. This means that when I want to solve the next Upper-Corner, I rotate the top layer clockwise, or counterclockwise, to place that Upper-Corner in the Top Right of the Front side which is facing me.
I rotated the Upper Layer to move the green-orange-yellow Corner to the Top Right of Photo 25. NOTE that I kept the Red Center square facing me. With the Yellow Center facing up, I perform the same algorithm to spin the Top-Right corner so its yellow tile moves to the right side of the cube.
I've spun the yellow tile from the Front Side of Photo 25, to the right side of Photo 26. I will perform the algorithm *again*, to move the yellow tile from the right side, to the top of the corner.
From Photo 26, above, I spun the last yellow tile to the top of the cube, and the algorithm returned a state of order to the rest of the cube. This re-solving of the bottom two layers is the most important achievement, the masterstroke, of the algorithm. I'm going to say that at this point, I think the Cube is basically solved. We know that the red Center-Square is always opposite of the orange Center-Square. We can see that if we rotate the Top-Layer counter-clockwise, those 3 orange squares on the right-side will go to their correct positions. At the same time, we will be moving those three green squares on the front-side to their correct positions.
When you correctly use this method to solve the Cube, once the yellow-squares are all facing up, it will be very easy to finish the puzzle.
If you get the Upper Layer solved, but the Lower and Middle layers are messed up, the most likely reason (as I've shouted repeatedly) is that you neglected the last D rotation on one or more of the above algorithms. Another common mistake is to *not* keep the SAME center color facing you the whole time you're doing an algorithm. If the bottom two layers resemble any of the previous stages, you might not have to go all the way back to the beginning. One idea is to look at the cube and try to solve the white layer again, and maybe this will pull the other pieces towards a stage you recently passed. Another idea is to flip the cube to make the solved yellow layer the Lower layer, and start solving the middle layer again, with the idea of making the white layer the Upper Layer to solve last.
An advantage of this method being so sequential is that it is easy to stop after any of the first five sections above, take a break, and come back to the cube later. Really, once you are familiar with the goals and the results for each of the sections above, it is pretty easy to stop after any completed algorithm, return the phone call you just ignored, and resume the cube at a later time. See below for exercises to drill these various algorithms into your brain memory and your muscle memory.
Here's the solved Cube after we rotated the Top-Layer counter-clockwise.
After i found directions like these online, it took me an hour or two to solve the Cube the first time. I kept working on it every weekend for an hour or two, and soon I started to memorize the algorithms. Within a month or two, I no longer needed to read the algorithms, because I had them memorized. For years now, I've solved the Cube once or twice on most weekends, and these algorithms have stayed in my memory. YMMV.
TLDR: Below is a summary of the algorithms used in this method. My belief is that these are HALF of what you need to solve the cube. The *other* half is the ability to look at the Cube, and SEE how to USE those algorithms.
UR U'R' U'F' UF
U'L' UL UF U'F'
F RU R'U'F'
RU R'U R 2U R'U
U R U' L' U R' U' L
R' D' R D R' D' R D
If you look around the internet, you can find other algorithms and multiple ways to solve the Cube. The method here is generally considered the easiest, and the beginner's method. If you want to solve the Cube in under 60 seconds, you want to choose another method. Basically, to solve the Cube in under 60 seconds, you need to memorize a larger set of algorithms, and be able to *see* how to *use* them.
I first learned the algorithms above, and this basic method, from Ruwix, which has a lot of other information about the Rubik's® Cube, and similar twisty puzzles. I often use their Scramble Generator.
You can also find plenty of information by looking at rubiks.com, or searching Wikipedia.
Wikipedia has articles about David Singmaster, which point out that his 1980 book Notes on Rubik's "Magic Cube" pioneered this layer-by-layer method of solving. The move-notation I use on this page is known as Singmaster notation.
One common method of memorization is to create a saying. Every Good Boy Deserves Fudge helps to remember the notes for the lines of the music staff: E,G,B,D, and F.
R' D' R D R' D' R D
For this algorithm, I think of Research and Development.
Research and Development Research and Development (x2).
Somehow, for me, I've always kept my memories of the *side* to turn, slightly separate from my memories of the *direction* to turn that side. Maybe this is a sign of psychosis, or maybe this is simply because the directions, being ternary, are easier to remember. The directions are either Clockwise, CounterClockwise, or 2. For the above algorithm, I think of the directions as:
' ' C C ' ' C C
I tie these two memories together by thinking of the idea, in business, that you have to go backwards (invest money/CounterClockwise) with Research and Development, before you go forward (make a profit/Clockwise) with what you learn from Research and Development. And again, to put these two memories back together, you end up with:
R' D' R D R' D' R D
RU R'U R 2U R'U
In general, it is probably more effective to create your own memorization phrase, but I'll share one more. This algorithm likely was the one that took me the longest to memorize. I don't think i could remember it consistently until I made up the following nursery rhyme. Remember, as explained below photo 14, 2U means we are turning the Upper-layer 180 degrees. Roo rhymes with "glue". "back" = backwards = counter-clockwise.
Roo Roo x2, Every-other-R back, Start with double-U, The second time through.
For me, this nursery rhyme works really well. Just don't forget the last R is backwards/counter-clockwise, so it recompiles as:
RU R'U R 2U R'U
After you've solved the Cube, one easy way to memorize the algorithms is to repeat the same algorithm over and over, starting with a Solved Cube. The above algorithms can be repeated a (mostly) small number of times, and the algorithm will bring the cube back to the solved state.
In other words, if you *Start* with a *Solved Cube*, and you perform any *ONE* of these algorithms repeatedly, that algorithm will soon solve the Cube again.
R' D' R D R' D' R D - 3x returns to solved. U R U' L' U R' U' L - 3x returns to solved. RU R'U R 2U R'U - 4x returns to solved. F RU R'U'F' - 6x returns to solved. UR U'R' U'F' UF - 15x returns to solved. U'L' UL UF U'F' - 15x returns to solved.
I've listed these algorithms in the order that i think you should study them. They are listed in the reverse-order from when you use them while solving the Cube. I'm calling the algorithm at the top of the list the most important to learn, because if you mess it up while solving the Cube, and you have to go all the way back to the beginning of your solve, you have farther to go. If you're going to fall while climbing the mountain, it is much worse to fall when you are one step from the top, and much better to fall when when you are one step from the bottom.
Also note, the first two algorithms used in your solve, are also the most difficult to practice. Returning the Cube to its solved position takes 15 repetitions of the first two algorithms used in your solve. The other algorithms take 3, 4, or 6 repetitions of the algorithms, to return the Cube to its solved position. If you practice these shorter algorithms first, you'll have a better chance of succeeding with the two algorithms that take 15x.