(Arthur imagines what it's like to be Mr. Ratburn, as we see from Ratburn's point of view...)
Mr. Ratburn: Ahem. Good morning, class. Let's start the day off with a little math quiz.
(The class groans softly.)
Mr. Ratburn: (in his head) Hmm. That wasn't a big enough groan. Maybe I'm getting too soft on them... (sees a pile of math exams on his desk)
Mr. Ratburn: On second thought, let's start the day with a big math test! (louder groan from the class, thinking again...) Ahh. That's more like it.