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Stone Hill Elementary School Library: Dewey Detectives

Essential Question

How does the library use categories to arrange the nonfiction section?

Lesson 1 - What's My Category?

  • Introduction: Ask students if they have collections at home. If needed to get discussion started, share some of my own collections (books, teapots, magnets, etc.). Ask volunteers to describe how they arrange their  collections. Answers are likely to include by size, color, team, etc. Ask someone to remind the class how fiction books are arranged. Explain that Melvil Dewey came up with the Dewey Decimal system to arrange nonfiction books. And that instead of lecturing to them, I’m going to have them figure out some of the categories on their own.
  • Group Work: Distribute a stack of preselected books from the 500s, 700s, or 900s to each table, along with some paper. Tell the students that their assignment is to write down the topics of the books they’re given, and then try to figure out how they go together into one overall category. 

    Monitor groups as they work. If necessary, if they can't figure it out, the two groups assigned to a category may come together to compare their topics and work as a large team.

    Once all groups have finished, have the two groups for each category call out topics they’ve written down to see if the rest of the class can figure out their answer.

  • Assessment: 

    1 = Group does not come up with category

    2= Group needs a LOT of prompting to figure out category

    3= Group comes up with category independently

    4 = Student's group comes up with category independently AND student figures out another group's category as well

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Lesson 2 - Where Would I Find This?

  • Prep: Have “game board” (see photo) and stack of cards (see file below) on each table when students arrive. I got the idea for this lesson from from Anne Oelke via LMNet.

  • Discussion: Remind students that we figured out Dewey categories last time. Ask them what the three categories – 500s, 700s, and 900s – were, and write them on the white board. Explain that this week’s assignment is the inverse of last time’s … they’ll be given a stack of “cards” with topics on them, and they have to figure out which category they belong in. Give a few examples so they understand what they’re supposed to do. Let them know that it's not a test; so long as they can explain why they put a card in a certain category, they'll get credit. 

  • Group Work: Monitor groups as they work. Question why they have selected certain categories for certain topics. Remind them that it’s not a test; I just want to know how they were thinking. Having a card in the wrong column isn’t a problem; having no justification for having done so is.

1 = Group has 6 or more topics in the wrong category and cannot sufficiently explain why.

2= Group has 3-5 topics in the wrong category without sufficient explanation.

3= Group has 0-2 topics in the wrong category


  • Individual Work: Let students know that the 100s categories are each split into 10 subcategories. Give them a list of the subcategories for the 500s, 700s, and 900s (see below; thanks to “The Beautiful Morning Story” at for the idea). They must read the story and fill in the correct subcategory for each of the missing words.

1 = 4 or fewer answers correct

2 = 5-6 answers correct

3 = 7-8 answers correct



Standards Addressed

AASL: 2.1.2 - Organize knowledge so that it is useful; 2.1.5 - Collaborate with others to exchange ideas, develop new understandings, make decisions, and solve problems; 3.1.2 - Participate and collaborate as members of a social and intellectual network of learners

Common Core: SL.1 - Engage effectively in a range of collaborative discussions with diverse partners; W.4.8 - Recall relevant information from experiences or gather relevant information from print and digital sources; take notes and categorize information …M7 - Look for and make use of structure; M.4.OA - Generate and analyze patterns