Setting up the problem is the hard part, not the arithmetic. Use suggested homeworks for upper level classes. I hate busywork. Provide answers to everything but do not require those that know how to do it to do it. Make tests at least somewhat cumulative.
Finance builds on the previous topics.
Always give a cumulative final. This may be the first time when the student looks at the big picture. I would rather have them there for 5 minutes than not at all. Connect with the students. If you are just a person there to teach, you probably won't.