Formats does not address this issue. My suggestion would be to consider the entries with multiple page numbers a bit like a subentry in index form...and run the page numbers immediately following the "Inquiry Skill: Classify" rather than putting those page numbers in the right margin. So for this one, treat it as a subentry to "Air Masses" and it just wouldn't have a page number in the margin.
If you come up with a better option, let me know!
Cindi