I think it's also referred to as the "electron configuration method". It's where you pick a side to start from, and you "snake" back and fourth through the rows until you've counted all the cubes. You go back to front, front to back etc. When you encounter a cube with a tower on it, you count the entire tower and keep moving onward.
I don't know if that was an adequate explanation. It's somewhat hard to describe this stuff verbally.