WHAT ROLE DOES GEOGRAPHY PLAY IN THE CENSUS?

About This Activity

In this activity, you will learn important words about geography and the census. You will discover how the U.S. Census Bureau (the government group that counts people) divides up land into different areas. You will also learn why they organize things this way.

What you will learn to do:

• Explain different types of census map areas.
• Figure out how information from these different areas can be used.

Topics you will explore:

• Boundaries (the edges of an area)
• Geographic areas
• Thinking about space and maps

Skills you will practice:

• Studying information
• Making conclusions

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Materials You Will Need

• The student pages for this activity
• A printed list of definitions

Activity Items

• Item 1: A short reading from the Geographic Areas Reference Manual
• Item 2: A chart showing how census areas fit together, from largest to smallest
• Item 3: Examples of census tracts, block groups, and blocks (three types of map areas)

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Important Words to Know

Spatial — Having to do with space on Earth's surface.

American Community Survey — A survey the Census Bureau does every month. It asks a sample of people questions to show how communities are changing. It collects information on things like education, income, housing, and jobs.

Decennial Census — A count that happens every 10 years. It counts every person living in the United States, based on where they lived on April 1 of that year.

Boundary — The edge or limit of an area, like a census block, county, or town. A boundary might follow something you can see, like a river or street — or it might not.

Geographic Hierarchy — A system where areas fit inside bigger areas, like nesting boxes. For example, states are divided into counties, and counties are divided into smaller pieces.

Geographic Entity — Any kind of area, such as a state, county, town, census tract, or country.

Administrative Entity — An area with official boundaries, usually without its own elected leaders, made to help run things like elections. Examples include school districts and voting districts.

Legal Entity — An area whose name and boundaries come from laws or official government actions. Examples include the United States, Puerto Rico, counties, cities, towns, and school districts.

Statistical Entity — An area used only for collecting and organizing data. It does not have official boundaries set by law, and it has no government power.

Small-Area Data — Census information collected for very small areas: census blocks, block groups, and census tracts.

Census Tract — A fairly small, long-lasting area within a county. Local groups help decide where these areas are. Each tract usually has about 4,000 people and 1,600 homes. Their edges usually follow things you can see, like roads or rivers.

Census Block — The smallest area the Census Bureau uses. Its edges can be things you can see, like streets or railroad tracks, or things you can't see, like property lines or school district borders.

Census Block Group — An area usually made up of 600 to 3,000 people, used to organize data.

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How the Activity Works

Before the activity: Your teacher will go over the words and definitions above with you.

During the activity:

1. You will read Item 1 together as a class, in small groups, or out loud with your teacher.
2. Your teacher will hand out slips of paper — some with terms, some with definitions. You will walk around the room and try to match each term with the correct definition.
3. Once you find a match, you'll place them together on the board.
4. Your teacher will help fix any mistakes and review all the terms with you, using Item 2 to show how the areas fit together from biggest to smallest.
5. You will look at Item 3 and answer two questions on your own.

After the activity: You'll share your answers with a partner. Then you'll try to write one sentence answering this big question: What role does geography play in the census?

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Extra Things to Explore

• Read a Census Bureau blog post about census blocks.
• Check out the Geography Data Gems for more fun facts about how the Census Bureau organizes maps.
• Explore the 2020 Census Demographic Data Map Viewer, an online map tool. It shows 2020 Census information for states, counties, and census tracts — including population, race, families, housing, and more.

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Student Questions

After reviewing Item 3, answer these questions:

1. How do census tracts, block groups, and census blocks compare in size? Which is biggest? Which is smallest?

Answer: Census tracts are the biggest. Census blocks are the smallest. Census block groups are in the middle.

(Hint: Be careful — sometimes small areas look bigger on a map because of the map's scale. Check the key carefully!)

2. How might people use information from these different areas? Why do you think it's helpful to divide land into these different-sized pieces?