## Rubik's Domino

Circa 1981: I was at a K-mart waiting in line to buy a handful of commodities, and there they were... an entire shelf of Rubik's Dominoes. There were about 100 of them on sale at the reasonable price of \$2 each. I thought, "Nyet! \$2 is still way too much for this puzzle." Famous last words; nowadays a Rubik's Domino will easily fetch at least \$100 on e-bay.

## F-

### I. Solve the White Pips (dark background)

A Rubik's Domino is basically a Rubik's Cube minus the "equator". Here are the laws of the Domino:

• The center tiles (with 5 pips) cannot move at all; all they can do is spin in place. Therefore, the center tile defines what color the entire face is suppose to become.
• A corner tile can move around and jump between faces, but will always end up in one of the 8 corner locations. Note how each corner (white or black, scrambled or solved) has an odd number of pips.
• An edge tile can also move around and jump between faces, but will always end up in one of the 8 edge locations. Note how each edge tile always has an even number of pips.

Solve the white pips (with the dark background) counting from left-to-right; in other words 1-2-3 for the top row, 4-5-6 for the middle row and 7-8-9 for the bottom row.

### 1. Solve the #2 tile

Hold the puzzle so that you are looking at the face with 5 white pips at the center. This side will be the front face for awhile.

 If the #2 tile is already on the front face, then merely rotate the front face until the #2 tile is at the top row. However, if the #2 tile is on the bottom face... ...then flip whatever row or column that tile happens to be on. Once the #2 tile is on the front, rotate the front face so that the #2 tile is at the top row.

### 2. Solve the other edge tiles

#### Move Up:

If an edge tile is already on the front face, but at the wrong spot... ...then knock it down, by flipping over whatever row or column it happens to be on. Afterwards, move it up to its correct spot during the next step. If (or once) an edge tile is on the back, then rotate the back face until the edge tile is directly below its destination... ...and then flip the row or column of that tile to move it up to its correct location.

### 3. Solve the corners

Now it's time to introduce yourself to the very first move you have to memorize:

## R F+ B F- R

#### What the move does:

It swaps the lower-right corners from front to back and visa-versa. It also wreaks havok on other tiles on the back-side, but we do not care about their particular fate for now (as long the other front-side corners remain intact).

#### Do the move:

A corner tile is already on the front side, but at the wrong spot. Rotate the front face until that tile is at the lower-right.

### R F+ B F- R

Now the corner tile is knocked down to the back face. Follow the next step to move it up.

#### Do the move:

A corner tile is on the back face.
SET UP: Rotate the back face so that the tile to-go is at the lower-right. Rotate the front face so that the vacant tile is also at the lower-right.

### R F+ B F- R

Now that the tile is moved up to its proper location... ...rotate the front face until all solved tiles are where they're suppose to be, just to get your bearings straight.