Which department is Dr. Smith in?

M: Math Department, Dr. Smith speaking.
W: Hello, Professor Smith, this is Janet Hill calling. I live two doors down from your teaching assistant, Don Williams. Don asked me to call you because he has lost his voice and can’t talk to you himself.
M: Lost his voice? Oh, what a shame! Is there anything I can do for him?
W: Well, he has a class this afternoon from 2:30 to 4:00 and he won’t be able to teach it. But he doesn’t want to cancel it either.
M: Does he want me to try to find somebody else to teach the class?
W: No, not exactly. What he wants to do is to get someone to go in for him, just to pass back the mid term exams. He’s already marked them and they are on the desk in his office. The whole thing wouldn’t take more than 10 minutes.
M: His classes are at 2:30, you say? Well I’m free at that time and I was going to be on campus any way, so I could do it for him. What room is his class in?
W: Cater Hall, Room 214: Will you need his office key to get the exams? He’s given it to me and I could bring it to you.
M: Actually, that won’t be necessary. We have a master key in the Math Department. So I can get into his office if necessary.
W: Thank you very much, Professor Smith. Don doesn’t have another class until Thursday, and hope fully he’ll be able to talk by then, He’ll call you as soon as he can. Oh, yes, I almost forgot.
M: Yes?
W: Could you put the next assignment on the blackboard too? 411 the questions are on page 45 on his notebook, and they are due at the next class.
M: No trouble at all. Thanks for passing on the news about Don. And please tell him not to worry a bout anything.