USA TODAY® Related Activities
Internet Activity
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.
|
