Supermarket offers: Bigger doesn't mean cheaper

Mathematics Professor Bernhard von Stengel explained how some supermarkets calculate their deals. He used his expertise in Game Theory to assess what really makes a good offer.

He said "part of game theory is optimisation."

In the game of special deals, both the customers and the supermarkets are trying to get the optimum value.

Professor Bernhard said "when I see a special offer I have to be careful. They are probably playing a game with me".

He advised shoppers to use 'basic arithmetics' to work out the unit costs, as the best way of comparing deals.