@ellythomas :
A keyword in your post is that you were "substituting" in a class. Students, who may be less self-regulated than most, may feel having a "substitute teacher" in their classroom opens a new door of opportunity for unbounded behavior. In the context of a substitute teacher, students may engage the idea there are no defined boundaries or guidelines; or for that matter consequences, so they feel empowered to "seize the day." If possible, I would consult the regular teacher on the classroom management guidelines she has in place and make the class immediately aware that I am supporting… >>>