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# Decimal Comparisons without Rounding

## Compare numbers written to a variety of decimal place values.

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Practice Decimal Comparisons without Rounding

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Decimals for Dewey

Credit: Tim Wechy
Source: http://www.flickr.com/photos/twechy/6977047957/

Have you ever looked around your neighborhood or school library? If you read the labels on the spines of the books, you?ll see lots of decimal numbers. These numbers help librarians make sure that books end up in the right place on the shelf, and they help library-goers find the books they want. They?re part of the Dewey Decimal System.

#### Organizing Libraries

Melvil Dewey published his library classification system in 1876. Before that, every library had its own method of sorting books. Different librarians would put the same book in different places. Some libraries even organized their books by size! Sometimes, the librarian would be the only person who could find a certain book.

Dewey?s system ensured that every library organized its books in the same order. Each book is assigned a Dewey Decimal number. The three-digit whole number designates a general category. The numbers after the decimal point indicate more specific topics. For instance, a book about the human heart is assigned the number 611.12. "611" tells you that the book is about the human body, and ".12" tells you it?s about the heart. If you go to that particular shelf in your library, you will find many books on the heart at 611.12.

Credit: Carol M. Highsmith

The Dewey Decimal System isn?t the only way to organize books. Most universities and museums use the Library of Congress System, which is more convenient for very large collections. With computers, how we organize information has changed. Some librarians want to create new systems, based on how we search for information today.

#### Explore More

Watch the following video about a high school library's decision to ditch the Dewey Decimal System. Then answer the questions below.

What are the advantages of the Dewey Decimal System? What are some drawbacks? If you had to create your own organization system for a library, what would it be like?

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