I have gotten confirmation that compasses would not work as desired on the moon, thus vindicating teenager-me being all like "but would it even work on the moon".

I'm also fairly certain it was the moon in the real world exercise, because multiple people have described having to do the same thing, and that the compass was one of the things listed. Therefore, I have either morphed the memories of a bunch of people, or this was a relatively common exercise for a long time.

In front of the class? 

Given the time crunch for getting this exercise done in one period with a full class, I honestly think it would be more realistic if they gave their answers while remaining in their seats.

I didn't feel that visual implied presenting to the class, however, so standing in front of the chalkboard it is. This class is so going to be scrambling by the time they hear the bell.