Hi Katherine: Sounds like you've got some time challenges there. Sometimes, we just have to work with what we have. If your institution allowed for this, perhaps you could have an activity assigned to students that occurs at the last 10-15 minutes of the first class. This might give you an opprtunity slip out briefy and take care of an errand. You might consider a student led discussion by one or more of your better students you trust to keep things in order in your absence. Regards, Barry