As more of the cube is built up, we will eventually find that we can no longer affect the pieces we want without destroying blocks that we have already formed. In these cases, we need to go ahead and destroy, but remember what we did so that we can restore it afterwards by using the inverse move.
Using the step button to step through each move individually:
- The first move shows that we can join the two green blocks in one move. This destroys the large white block, but remember that we can restore this white block by doing the reverse of this move: i.e. rotating the front face 90 degrees anti-clockwise will restore the white block.
- From here on, we use the move it out of the way strategy. We have joined the green pieces together, and the next thing we want to do is restore the white block. However, the green block is now "in the way". If we want to restore the white block, we need to move the green block out of the way. The second move does that.
- With everything moved out of the way, we finally restore the white block. This is the reverse of the first move.