how do you count?

I am wondering how other members of AACL count short sessions that are provided as part of the information literacy program. In our statistical comparisons we distinguish between tours and classes but how do you count sessions that aren't either? For example, on New Student Orientation Day we attended about 25 classes to give short (10-15 minute) introductory talks on the Library to classes that ranged in size from 3 students to 150 students. They required preparation and presentation time plus helped us reach the students on their first day - so they are important. But they didn't require the same amount of work as our regular info lit classes do, so we don't know how to count them.
How do you count these or do you not include them?
Thanks.
Keith