The teacher is there to make sure that everyone gets a chance to learn and participate in all activities. If everyone misbehaved at the same time, the classroom would turn into a zoo. That is why you should always be polite to the teacher, and say please and thank you whenever you can. Also, you should never talk while the teacher is talking. If you have something to say, then the polite thing would be to raise your hand. You should be ready with your homework when the teacher comes around to check it, as well as have all your materials ready to begin a new a new lesson.
You should always treat other students the way that you want to be treated. That means if the teacher calls on another student, let them speak. No one likes to be interrupted, so it is not polite to talk when others are talking. Never steal from someone's desk. Do not make fun of someone, especially if he gets an answer wrong. Also, always try to be helpful to other students when possible.
It may be called a student desk, but that does not mean it should be messy. Always put away your materials neatly, especially when the teacher says to do so. Do not leave everything out in the open, especially on someone else's desk. If there is a chair, always make sure it is pushed in under the desk before you leave.
Sometimes the teacher will bring someone in to talk to the class. Whoever it is, whether it is another parent, policeman or the principal, always respect this person by using good manners. Listen to what they have to say, and do not interrupt them unless they ask a question. After she is done talking, say thank you to before they leave. That will make the person feel special, and just might make her want to come talk to the class again.