Math Problem

Where did the money go?

There were three friends having dinner together, when the waiter brought their bill, which was $30. Each paid $10.
After collecting the money the waiter realized that t he bill should have been $26 insted, dua to a special discount.
Unsure on how to divide $4 equally among three people, he put $1 in his pocket ang gave each person $1. This means that each person paid $9 for their dinner.
It happens that 9 x 3 + 1 = 28. What happened to the other $2?

There are no two other dollars.  $9 x 3 = $27.  Minus the $1 the waiter took, and you have the $26.

Another way to think of it is that the $9 each person paid is postive becuase they go towards paying for the bill.  So +27.  But the dollar the waiter took doesn't go towards paying for the bill, so it's negative.  Thus +27 -1 = +26.

It doesn't make sense to think of it in the way the teaser suggests.