Princess on the Brink

Princess on the Brink, also known as After Eight in the United Kingdom, is volume eight of The Princess Diaries series.

Description
"In the eighth Princess Diaries novel, Princess Mia finds herself facing some very difficult problems. She's a junior now, and even though she survived freshman Algebra and sophomore Geometry, there's no guarantee she'll make it through Precalculus. On top of all the mathematical strife, her beloved boyfriend, Michael, is leaving for Japan for a year. Precalc has nothing on preparing for the worst separation ever!"