Dan Gutman 
My Weirder-est School #9: Mrs. Barr Has Gone Too Far! 

With more than 30 million books sold, the My Weird School series really gets kids reading! In this ninth book in the My Weirder-est School arc, A.J. and his friends learn some new, exciting facts about geography from a world traveler. No need to pack your bags for this trip! After noticing that A.J. and his friends geography knowledge could use some work, Mr. Cooper invites to class just the person to help. Globetrotter Mrs. Barr speaks seven languages and has visited nearly two hundred countries! But why does she carry a suitcase everywhere she goes? And why does she open a window whenever she walks into a room? Perhaps Mrs. Barr has something to hide! Perfect for reluctant readers and all kids hungry for funny school stories, Dan Gutmans hugely popular My Weird School chapter book series has something for everyone. Dont miss the hilarious adventures of A.J. and the gang!