OH NO!!!! The student changed periods and their grades are GONE!!!
Not really. Here's how to find them!
Open the class the student dropped.
Look on the left hand side of the screen for "Dropped" and click on the little triangle next to it to open the drop-down.
All of the students who have dropped this section of the course appear in the list.
Select the one you want to see grades for and change the drop down menu above to "Filter Selected"
You will now see just the student(s) you selected from the Dropped Students List.
You can print a scoresheet report for this one selected student to make it easier to input grades into the other period.
I wish I could tell you that these could be copy/pasted, but that just isn't a functionality we have at this time.