"Do-We" Know Dewey?
A great way to teach the Dewey Decimal system concept to kids is to break it down into a really fun activity. This is perfect for a class visit or scout tour.
Talk to the kids about how the library is organized a lot like a grocery store. "Like" things are kept together. Milks together; toothpaste together; candy together. You wouldn't find frozen ice cream in the lettuce or look for cereal with the cheese. The dewey decimal system is just a way to keep books about the same stuff together.
Mention that the Dewey Decimal system is also like a world language. Ask the kids if they know words in any other language - you'll get lots of polyglot talk back! Then tell the kids that your world language is "Dewey". When you want a dinosaur book you know that 567=dinosaurs; or 398=folk and fairy tales or 636.7=dogs. Then walk them along the non-fiction and explain (briefly) the major areas and point out subjects popular to their age level.
Finally, the piece de resistance! Catalog, barcode and shelve the kids! Just ask them for a a favorite subject, write a corresponding dewey number on a sticker and put that and a barcode on the kids. Then put them in order and "shelve" them in their part of the collection as you walk along with them!
They have a great time and many kids really "get" it. And you always reassure them that staffers are there to help them translate dewey and find the books they want quickly and easily whenever they return!