USA TODAY® Related Activities

 Internet Activity Teacher Notes

Farms in America

Materials: calculator, spreadsheet software (optional), grid paper

Work alone or in a pairs.

The table shows the approximate number of U. S. farms, in millions, and the size of farms, in acres for various years.

 Year Years Since 1940 Number of Farms (millions) Average Number of Acres Per Farm 1940 0 6.2 174 1950 10 5.6 213 1960 20 4.0 297 1970 30 3.0 374 1980 40 2.4 426 1999 49 2.2 432

Source:The World Almanac

Procedure for the Activity

Step 1  Write six ordered pairs (years since 1940, number of farms). Graph the ordered pairs on a coordinate axes. Connect consecutive points with line segments. Describe the graph.

Step 2  Find the rate of change for each line segment in the graph from Step 1. List the values in a table like the one started below. What do the values for the rate of change represent in this situation?

 Years Since 1940 Number of Farms (millions) Rate of Change 0 6.2 — 10 5.6 20 4.0 30 3.0 40 2.4 49 2.2

Step 3  Find the average of the rate of change values in Step 2. Find the rate of change using only the ordered pairs (0, 6.2) and (49, 2.2). How do the values compare?

Step 4  Write six ordered pairs (years since 1940, average number of acres). Graph the ordered pairs on a coordinate axes. Connect consecutive points with line segments. Describe the graph.

Step 5  Find the rate of change for each line segment in the graph from Step 3. List the values in a table like the one started below. What do the values for the rate of change represent in this situation?

 Years Since 1940 Average Number of Acres Per Farm Rate of Change 0 174 — 10 213 20 297 30 374 40 426 49 432

Step 6  Find the average of the rate of change values in Step 5. Find the rate of change using only the ordered pairs (0, 174) and (49, 432). How do the values compare?

Step 7  What is the relationship between the two sets of data—years versus number of farms and years versus size of farms?

Wrapping Up the Activity

Research agriculture in your state. Find out how the number of farms, size of farms, and people employed in agriculture has changed in the past decade. Write a one-page summary of your findings. Include a graph displaying some data about agriculture in your state.

Washington