Con artists take note..

Three men go into a restaurant and order a meal. The bill turns out to be £30 so they each pay a tenner. The waiter takes the money to the till whereupon the manager decides to give his customers a £5 discount. The waiter takes five £1 coins from the till, gives one to each of the men with the manager's compliments and pockets the other two £1 coins himself.

If the men each paid £10 and got £1 back then the meal cost them £9 each. Since three nines makes £27 and the waiter only stole £2, where has the other pound gone?

Answer on a postcard please.....