The boy is acting like he doesn't know the value of the dollar or the quarter so that the barber can keep giving him quarters. Let's say this game has been going on for a month every day, the boy would have made 30 quarters which is 7 dollars and 50 cents in total because all he did daily was to choose the quarter over the dollar. Now if he just picked the dollar, then the barber would have understood that the boy isn't actually dumb and hence he'd stop trying to prove to everyone that he's dumb by telling him to choose between the quarter and the dollar. PS I tried my best to break it down idk if you're still confused 😪