A census is an official count of all the people living in a country, state, or region. Every ten years, the United States conducts a national census to find out exactly how many people live in each state, city, and neighborhood. Census workers try to count every single person, from newborns to great-grandparents.

The census also gathers information about age, family size, and where people live. This data helps governments make important decisions: how many new schools to build, where hospitals are needed most, how to plan roads and bus routes, and how much money different communities should receive for public services.

The U.S. Constitution requires a census every decade because population numbers determine how many representatives each state gets in Congress. States with growing populations gain representatives, while states that lose population may lose seats.

Taking an accurate census is surprisingly difficult. Census workers must reach people in remote areas, apartment buildings, and everywhere in between. They work hard to make sure every person is counted, because decisions based on census data affect communities for the next ten years.