If you want a technical definition: if X is precisely N orders of magnitude greater than Y, then X = (10^N)Y. Thus 110 million, being between 80 million and 800 million, is between one and two orders of magnitude greater than 8 million. A more exact figure, if we want to get logarithmical, is that 110 million is 1.14 orders of magnitude greater than 8 million.
To say that 110 million is two orders of magnitude greater than 8 million is probably to play somewhat fast and loose with the definition of an "order of magnitude;" David was likely thinking in terms of how many more digits the one has than the other. Myself, I'd tend to say that a number would have to be at least 253 million (it is 1.5 orders of magnitude greater than 8 million, which rounds to two) before I'd call it two orders of magnitude greater than 8 million.
Perhaps there is an accepted definition of "order of magnitude" which is defined solely by how many digits are in a number; if so, then this sense is far less precise, defining 1000 to be an order of magnitude greater than 999 (for example). If such a definition exists, it would fit with David's statement.
--Brian
