Hummer - don't fret about it. It was probably given as an exercise just to see how well you trusted your work. I can imagine many different answers coming out of this, but also people re-doing it when they came up the the 610.something, thinking that must be wrong - as you may have by expecting something nice and clean. You where looking for that before you ever started! Also, it's not an irrational number for an answer in math sense, but in people thinking sense it is.
I do like the other method - breaking it down first and doing it steps. Very elegant and thinking outside the box!