Reply By G.M.

I don't really have an answer for you. I just wanted you to know that I have the same question.
What should a sub expect? How quiet can you keep a class? I think it depends on a lot of things.

I subbed for a second grade teacher the other day.
She instructed me to "insist" on no talking during centers while I was at the guided reading table with a small group. I had to stop about every 5 minutes because several students were talking to their neighbors.

After the second warning, I took some recess times from them. Posted the time on the board. There were many gasps! Oh no, we don't have all our recess. I thought, okay, know I've found the key! But no . . . a few mintues later, they were back to whispering to their neighbors. I took 2 minutes of recess again, post that on the board.
Gasps again . . .
and a few minutes of silence followed. Then whispering followed AGAIN. I calmly got up and took another 2 minutes off. Total minutes lost of a 15-minute recess was 6.

Subbing is usually harder than having your own class because when you sub, it usually throws the younger kids off - they want THEIR teacher, not you. Usually, the kids seem to like me, however.
Some older kids see you walk in and think you don't know anything. Therefore, they test you. Sometimes, they administer their tests all day.

All in all, I have found subbing is more difficult than having your own class in many ways.
However, it is good experience and helps you get a feel for the school. And I get a good feeling knowing that I am doing my best to help out another teacher. I had my own class last year (my first year). I am subbing this year to learn where I would like to possibly teach next year.
That's my primary reason for subbing.

I hope someone with more subbing experience can answer our question: How quiet can we expect a class to be when we sub?

You are not only; remember that when you are standing in the classroom trying to quiet them down.

sincerely, G.M.