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Welcome Library Explorers!

What is Library Explorers Club?


What are those numbers at the bottom of the spine of the book? Come and find out!

Join us every month as we explore a different class in the Dewey Decimal System! Learn how to find books around the library, and have a chance to impress family and friends with interesting facts! 

Work at your own pace at home over the month or join us on the last Saturday of the month!

How it works:

There will be different themes each month related to a particular Dewey Decimal range. Each month, you will

  • Choose a nonfiction book (or audio book or watch a documentary or episode from a non-fiction television show) from one of the themes and share something you found interesting.

  • Choose 1 of the activities within that theme. There are 4 options. You only have to do one. Anything beyond that is optional!

  • Don't like the themes? Go with the Free Choice option!

Track your progress online through Wandoo* or a paper Library Passport.

Explore the library over the course of the year to collect digital badges or Passport stickers and earn prizes!

You can find descriptions of each month's Dewey Decimal range, activities, and anything you may want to print below!

*Wandoo Reader is the website used for the Online Summer Library Club. If you tracked or logged your reading online this summer, you can use the same log-in information!

April 2020 : Explore the 800s!

Coming Soon

Current Themes






Free Choice!

Choose any other topics covered by the 800s and share an interesting fact you learn! 

There are no specific activities for free choice! To earn your badge, make something or write a story related to the topic you chose!




What is the Dewey Decimal System?

The Dewey Decimal System is a way to organize books in a library based on subject - what they are about. It was created by Melville Dewey in the 1870s, and first published in 1876. 

It is designed using base 10 (yes, math).

There are 10 Classes

000 - General Knowledge; 100 - Philosophy & Psychology; 200 - Religion; 300 - Social Sciences; 400 - Language; 500 - Science; 600 - Technology; 700 - Art & Recreation; 800 - Literature; 900 - History & Geography

which are broken into 10 divisions

500 - Science; 510 - Mathematics; 520 - Astronomy; 530 - Physics; 540 - Chemistry; 550 - Earth Science & Geology; 560 - Fossils; 570 - Biology; 580 - Plants; 590 - Animals

which are further divided into 10 sections

590 - Animals; 591 - Specific topics in natural history of animals; 592 - Invertebrates; 593 - Miscellaneous marine & seashore invertebrates; 594 - Mollusks; 595 - Spiders and Insects; 596 - Fish; 597 - Cold-blooded vertebrates (reptiles & amphibians); 598 - Birds; 599 - Mammals

These whole numbers are followed by a decimal point, and the decimal number that follows allows books to be sorted into even narrower categories.

599.1 - Platypus; 599.2 - Marsupials; 599.3 - Rodents & Insectivores; 599.4 - Bats; 599.5 - Whales & Dolphins; 599.6 - Elephants & Hooved animals; 599.7 - Cats, Dogs, and Bears; 599.8 - Non-human Primates; 599.9 - Humans

And they can go on and on! Dewey Decimal numbers can be very broad, stopping at just one, two, or three decimal points, or they can be very specific!

As you use Dewey more, you'll notice that some numbers are almost repetitive - General science experiment guides will be found at 507. Collections of Physics experiments will be found at 530.7, and Chemistry experiments will be under 540.7! 


Problems with Dewey:
The Dewey Decimal System isn't perfect. Some of the complaints people have are:

  • It has an inherent bias towards the Western world (Europe and the United States). In the 200s (Religion) Christianity gets 7 divisions! Other world religions have to share just 1 division, and religious beliefs from a variety of cultures, including Africa and Native Americans, are not even in the 200s but are included under fairy tales and folklore! 

  • Language choices can be demeaning - For example, "Social Problems" doesn't sound too bad... until you realize it classifies physical disabilities, learning disorders, and mental health under "Social Welfare Problems!" 

  • Times change, and some topics, such as feminism, women in general, and minorities, were not given much importance by society or Melville Dewey in the 1800s and therefore don't have good call number options.

  • Topics don't always stay together. Are you interested in learning more about the military? Check the 350s for general information about branches of the military, the 623s for books about military vehicles and equipment, and the 900s for specific battles, wars, and units!

So why do we still use it? In short, no library cataloging system is perfect, and many of the established systems have the same problems as Dewey. We could create our own cataloging system, but this is a lot of work and basically means reinventing the wheel. Instead, we've chosen to continue using Dewey while keeping these limitations in mind and doing our best to work around them. 

Past Themes


Oct. 2019

The 000s are home to several topics: Libraries, computers and coding, world records, encyclopedias, and the unexplained.

Click on the following call numbers to download the activities for that topic!

001.9: The Unexplained

UFOs, Bigfoot, and hoaxes, oh my! 001.9 is officially called "Controversial Knowledge" and includes cryptozoology, aliens, hoaxes, superstitions, and what's known as errors - things people often think are true but aren't!

020: Libraries

Libraries are more than just books, and this call number range shares secrets about what librarians do all day and about libraries around the world! There are even books about the Dewey Decimal System found here!

032: World Records

Tallest, Fastest, Oldest, First! These superlatives can be found in collections of records.

100s & 200s:

Nov. 2019

Click on the following call numbers to download the activities for that topic!

The 100s are home to several topics:  philosophy, parapsychology, brain research, dreams, optical illusions, astrology and feelings/emotions. Here you will find books on how we think.

Click on the following call numbers to download the activities for that topic!

152.148: Optical Illusions

What is really there? Can we trust what we see? How do we see things?

The 200s are home to religions of the world and myth. Here you will find books on what we believe.
290: Other Religions
You will find information about ancient religions and religions around the world.

300s & 400s:

Jan. 2020

Click on the following call numbers to download the activities for that topic!

The 300s Class is called “Social Sciences” and it houses numerous topics including books about government, sociology, anthropology, civil rights, the military, and immigration. It’s also home to fairy tales and folklore, etiquette manuals, and books about customs and holidays.

The 300s is one of the more problematic classes in Dewey. The language used to describe various subdivisions is often considered outdated, and many topics, especially those related to LGBTQ+ and women’s rights, don’t have good categories. Finally, the folklore and fairy tales section doesn’t just include stories such as Cinderella, Aesop’s Fables, and Paul Bunyan, but also origin stories and tales from the belief systems of Native American, African, and other indigenous peoples – essentially not recognizing their beliefs as valid religious practices.
Dewey continues to be used despite these flaws because it is still better than nothing, and other options suffer from many of the same problems.

320s: Political Science
The 320s include information on systems of government, voting, the Civil Rights Movement and more.

330s: Economics

This call number includes information managing money, how money works, and different economic systems.

The 400s Class is called “Languages” and it includes dictionaries in different languages as well as information on the alphabet, grammar, and spelling.

400s: Languages


Feb. 2020

The 500s are generally one of the largest non-fiction section in every library Children’s Room! The overall theme for the 500s is Math and Science. Here you can find books about science experiments, outer space, dinosaurs, insects, reptiles, physics, chemistry, earth science (like weather and volcanos), birds, plants and mammals. Yes, it is a lot!

Don’t forget that Maynard Public Library has discounted passes to several area museums where you can learn a lot about the topics in the 500s. Try: Boston Children’s Museum, Discover Museum, MA State Parks Pass, The Ecotarium, Drumlin Farm, Boston Museum of Science, New England Aquarium, Tower Hill Botanic Garden and Zoo New England.  More information about the passes is on our Website.

Click on the following call numbers to download the activities for that topic!

500s: Science Experiments

Yes!  Try these at home!

520s: Astronomy

Stars and Planets

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