Mrs. Roopy is Loopy by Dan Gutman

This book was about a boy named A.J. and his classmates. A.J. did not like school or reading books. The librarian Mrs. Roopy kept trying to get the students to be interested in books. Everyday she would dress up in someone different from famous books and nursery rhymes. Some of the characters she dressed up as were George Washington, Little Bo Peep, Johnny Appleseed, Jill, and Neil Armstrong. The students tried to figure out if they were all Mrs. Roopy. Mrs. Roopy dressed up as a biker to get A.J. to like school and reading books. At the end they find out that it was actually Mrs. Roopy dressing up in all the costumes.