Seems you and several others had the same idea. Good exposure on the shot. As I told the other person, I think it would have been interesting to see a nonverbal way to indicate counting. A hand pointing, a tally sheet, a calculator...
lol very good idea, and this picture looks great! I think the white background could be a bit brighter if you adjusted curves in PS a little more - but its not that big a deal. Great job!