5x5x5 Last two edges — the inner wing — Big-cube parity

Big-cube parity on the 4x4x4 to 7x7x7. The algorithm is 2U' R U R' F R' F' R 2U — 9 moves. The middle edge piece of a 5x5 is fixed, so the inner wing pairs against it with the inner slice instead of the outer one. This algorithm moves 15 edge pieces and 5 corners — fine during pairing, before the 3x3 stage.

The algorithm

2U' R U R' F R' F' R 2U. Read it as the cube faces you: U is the top face, R the right, F the front. A prime (') is anticlockwise, a 2 is a half turn, a lower-case or w-suffixed letter turns two layers.

When it applies

Edge pairing. The middle edge piece of a 5x5 is fixed, so the inner wing pairs against it with the inner slice instead of the outer one. This algorithm moves 15 edge pieces and 5 corners — fine during pairing, before the 3x3 stage.

How it is checked

Every algorithm on this site is applied to a real model of its cube in the test suite and asserted to solve its case and touch nothing else. It was proved, not proofread. Practise it from the timer, or add it to a printable sheet.