Lesson 7
Match the edges of the yellow cross with the centres of the side faces.
Goal: match the four edges of the yellow cross with the side centres. When it is done, the side colour of every top edge matches the centre below it.
Turn the top layer so as many edges as possible have a side colour that matches the centre below; at least two edges match. Whether the two matching edges are neighbours or opposite decides the case. If all four match, the stage is done.
The two matching edges are neighbours. Rotate the whole cube so they are at the back and on the right. Do swap edges (R U R' U R U2 R' U); all four edges match.
The two matching edges are opposite each other. Do swap edges (R U R' U R U2 R' U) from any side; after you turn the top layer again, two neighbouring edges match.
Turn the top layer: the side colours of all four edges match the centres below. No algorithm is needed.
If the two matching edges are neighbours, rotate the whole cube to put them at the back and on the right, then do swap edges (R U R' U R U2 R' U). If they are opposite, do the algorithm once from any side; after you turn the top layer again, two neighbouring edges match.
Yellow edges
R U R' U R U2 R' U
When: When the yellow cross is made but only two edges match their side centres. Hold the two neighbouring matching edges at the back and right.
Finger tip: It is two similar halves: R U R' U and R U2 R' U. In the second half push the top layer twice.