Hi Christina:
You're being very rsponsive to theneeds of the material to be presented vs the needs of the students to learn it.
An aternative view of back up plans is to have something, relaively meaningful, that can pull off the shelf and initiated without much preparation. This is for "one of those days" when nothing seems to be going as planned. When it happens, these kind of bak-up plans are simply invaluable.
Regards, Barry
