When you go to the cinema, it seems to be an unwritten rule that you must buy some popcorn to enjoy while you watch your film - even if half of it is gone by the time the trailers start.
But what size do you order?
While it might be tempting to go all out and spend more money securing a large portion of popcorn that will see you through the whole film, one cinema worker has confessed you're probably not making the most out of your money by doing things this way.
