The library, whether school or public, is the most logical place to practice Dewey classification skills. Pass out a worksheet listing each Dewey class or subdivision with which you wish students to familiarize themselves. Students spread out and find each section of the library shelves. For each section, they write down five to 10 titles that they find there.
After an introduction to the basic classes in the Dewey system, a game show activity can reinforce the students' classification skills. Divide the class into 2 to 4 teams and give each a summary sheet of the numbering system. Call out a book title and ask students to identify the call number that indicates which section this book would be shelved; or give a call number and ask students to name a book that would belong in that section. Teams can take turns answering or compete to "buzz in" and give the answer.
When new books come into the library, the librarian must determine the correct categorization and assign them call numbers based on the Dewey Decimal System. Give students a basket full of new books and a Dewey classification summary. Challenge them to correctly classify and label each book. If you can arrange it with a school or public librarian, students can spend a few hours helping process and label new acquisitions or shelve returned books for hands on practice with organizing books by Dewey's system.
Some people have personal shoppers. Students can pretend to be "personal librarians" to collect all the titles on your book list. Give each student a list of call numbers and have her race to bring you all the books you have requested. Each list should be different to avoid conflicts that prevent an individual from reaching her goal. A more challenging version would be to give only the title and author so the students have to use the card or computerized catalog to find the call number before they can locate the physical book.