It's difficult to grasp how big world population is without breaking it down in understandable terms. Image: luoman/iStockPhoto.com.
whole-class exercise helps students understand populations density and
spacial relations in understandable, comparable terms. Students, with
some classroom tools, will learn about Japanese population density;
Chinese population growth; and hypothesize about Mexican immigration
Through this activity, students will:
- Visualize approximate and relative sizes of the world's regions and populations.
- Use comparison and analogies to gain a clearer understanding of the world in which they live.
Early anthropologists sometimes characterized tribes by their ability
to deal with abstractions. I was amused by accounts of languages that,
in dealing with numbers, had only "1, 2, 3, many" until I tried to help
students visualize the landscapes, populations, and land-use problems
in regions we were studying. This led to the "three chair game."
At 50,000 square miles per chair, three chairs represented the
approximate area of California or Japan. With students representing 10
million people each, two students provided the population of California
(at that time!). There was plenty of room for them on the three chairs.
Eight or nine students had to sit on each other's laps to show the
population of Japan (again, at that time). The ones on the bottom
really grasped the concept of population pressure! If you are teaching
about population and resources over time, it would be enlightening for
the students to use this exercise to see how population now differed
from when their grandparents were growing up. The same comparison, on a
different scale, could be made of the United States and China.
But as a student reminded me after a visit to Japan, not all
of any country is as densely populated as the game implies; huge areas
of Japan are as sparsely populated as Montana. At this point, the "three
chair game" became the "twelve chair game."
This activity is based on the following premises: (1) Students
can understand any concepts or data presented in terms of their own
experience; (2) Abstractions are meaningful only to their makers; and
(3) All learning is by comparison--finding a connection between
something known and something unknown. (Please note that, to make
conceptualization easier, all numbers in this activity are
- When beginning the study of a region and its people,
initial questions to ask students include "where?" "how big?" and "how
many?" After locating the region (preferably on a globe so that its
relative size and relationships with other regions are not distorted),
ask for area and population estimates--in the case of this activity,
for Japan and Montana (Montana is the closest of the states to Japan in
area--each is approximately 146,000 square miles-- but is radically
different in almost every other way). Accept all guesses.
- Now, have students look up figures in a recent world almanac or on
the Internet. If one chair = 12,500 square miles, about how many chairs
would be needed to represent Montana or Japan? (12. Therefore, set out
12 chairs.) Have them calculate larger areas, such as regions, using a
16" globe (on the surface of which 500 miles = 1 inch) and a flexible
- Next, explain that forested mountains, too steep for farming or
easy logging, make up 2/3 of Japan's landscape (overturn 8 chairs); dry
grasslands, 1/24, and beaches and dunes, 1/24 (overturn 1 chair); over
3,000 tiny, mostly uninhabited islands, 1/24, and thin, poor soils
eroded by short, torrential rivers, 1/24 (overturn 1 more chair). The
remaining 1/6 (2 chairs) is suitable for agriculture but is
increasingly urban (nearly 1/2 of Japan's population is concentrated in
the Tokyo, Nagoya, and Osaka areas).
- What about Montana's 12 chairs? The partly forested Rocky Mountains
run through the western 1/3 (overturn 4 chairs), leveling out into dry
grasslands (2 chairs) and grasslands watered well enough for grazing
(overturn 4 chairs), leaving, like Japan, 1/6 (2 chairs) for cropland.
- Students can use classroom or library resources to calculate the
number of chairs that should be overturned for the landscapes of other
regions. Start with your school's state (3-way comparisons are
preferable to 2-way because they avoid "we-they" polarization).
- What about population? If one student represents one million
people, how many will represent the population of Montana? (Barely one
in 2006). Japan's population? (127 students based on 2006 figures).
With two chairs, one student has a choice of seats, but 127 students on
two chairs is pretty severe crowding, even with Board of Education
mandated class sizes!
- Stress to students that unlike area, which remains constant
(although some internal categories may change with good or poor land
management), populations are constantly changing. Therefore, population
numbers always must be qualified by dates. In the last 40 years,
Japan's population has increased by half and Montana's by a fourth.
- Population, like interest on savings accounts, increases
geometrically. Teach your students the Rule of 70: anything increasing
at the rate of 1% will double in 70 years; 2%, 35 years. See the
Population Reference Bureau figures for the world's countries. Note
that some African countries have growth rates of nearly 4%; their
populations will double in less than 20 years. Can students see the
reasons for China's campaign to persuade families to limit themselves
to one child? With their calculators and the Population Reference
Bureau website www.prb.org estimates of rate of increase, students
can make projections for various regions. Have them calculate Mexico's
increase and consider its potential effect on immigration statistics.
- Back to area. Montana has about 28,000 square miles of cropland,
Japan about 24,000. But, we are accustomed to think of farmland in
terms of acres. How many acres are in a square mile? (640). Acres of
farmland for Montana? (17,920,000). For Japan? (15,360,000). But how
big is an acre? On looking it up, students find that it is 43,500
square feet. Not much help. Can they visualize a football field? How
many square feet? (160 x 300 = 48,000). Each Montanan can enjoy-or
export-the crops that could be grown on 22 football fields! What about
the Japanese? (.122 acre=78 square feet). Have the students mark an 8 x
10 foot rectangle on the classroom floor to help them visualize this
Author: Elgin Heinz