3 people go to a restaurant and have a meal. The total meal comes to $3.00

Afterwards the proprietor of the restaurant realises he has overcharged the 3 people by $0.50, so he gives the $0.50 to the waiter to give to the 3 people. However the waiter appreciates that it will be difficult to divide the $0.50 by 3, so he gives each of the people $0.10 and keeps the remaining $0.20 for him self.

Each of the 3 people have effective paid $0.90. 3 time $0.90 equals $2.70, plus the $0.2O the waiter kept comes to $2.90. As the meal cost $3.00 what happened to the other $0.10?

It is all mathematics, so it should work out, so why the missing $0.10?

Sometimes when trying to explain the missing $0.10, by writing the numbers ,formulas or reversing the process, some people come up with an explanation. But if asked what is wrong with the about Summary and Problem, they cannot say.

Ther are 2 things wrong with the above Summary and Problem. First the meal did not cost $3.00. It cost 2.50. Second, the $0.20 the waiter kept, should not be added, it should be subtracted, because it was not part of the cost of the meal.

The summary should say, each of the 3 people have effective paid $0.90. 3 time $0.90 equals $2.70, less the $0.2O the waiter kept, comes to $2.50. The the meal cost $2.50

When I used to teach accounting, as part of a computing course, I would give this problem, without the solution, to students, prior to teaching bank reconciliations. I would provide the solution before teaching bank reconciliations.

It something helped students realise that they had to understand the logic of when you should add or subtract when reconciing a business bank account balance with the banks record of the business bank account. What bank reconciliations are about.

It can be very easy to confuse people with all sorts of reconciliations. Politicians, bureaucrats and business people have been known to do so.