Power of the Pyramids - Population Education

Power of the Pyramids
Student Activity
Method:
Students construct and interpret population pyramids and discuss differences in
population growth rates among several different countries.
Introduction:
Concept:
To help them make population projections for different countries, demographers
(who study population) look at the profile of the countries’ residents. What are the ages
of the people? How many are men? How many are women? Taking this information,
they construct population pyramids like the ones students will create in this activity.
These graphs depict the configuration of a country’s population as impacted by 70 to 80
years of economic, political, and natural events. These graphs can also help predict
future population trends.
Objectives:
The age and gender distribution of
a regional or national population
affects its growth rate and provides
information on its past, present,
and future growth patterns.
Students will be able to:
• Calculate percentages using raw
numbers for each age/gender group
in a given population.
• Construct a population age/
gender distribution graph for one
of six different countries.
• Make correlations between the
shapes of the graphs and the
growth patterns of different
countries.
Procedure:
1. Display the world population pyramid and explain that this is a kind of
graph used by demographers to study
the distribution of people across age
and gender categories.
2. Explain to the students that the
graph represents the entire world
population sorted by age and gender,
with the youngest at the bottom and
the oldest at the top. Each age level
grouping is called a cohort.
Subjects:
Mathematics, biology, social
studies, environmental science
3. Assign each student or group of
students one of the six countries, and
distribute graph paper and a copy of
the student worksheet for that country.
Skills:
Calculating, graphing, analyzing
and interpreting data
4. The figures on the worksheet
represent the population (in thousands) of each age group within each gender for each
particular country. In order to construct the country’s pyramid, students must first
calculate the percentage of the population of each gender in each age group.
Example: According to the worksheet, the United States’ total population in
2015 was 321,369,000. The population of males ages 0-4 was 10,211,000.
10,211,000 - .032 or 3.2%
321,320,000
Students should complete these calculations for each cohort.
5. Using graph paper, students can construct a population pyramid as in the example. A line
drawn down the middle of the graph separates the male and female populations. The percentages of the population will be plotted along the X-axis with females to the right of the center
line, males to the left. The age groups will be running up the Y-axis with the youngest at the
bottom, oldest at the top. (See “World Population Pyramid” for an example.)
Materials:
Copies of student worksheet
Power of the Pyramids graph paper
Colored pencils
Rulers
Calculators
Key Terms: cohort,
demographers, population pyramid
6. Have students graph the percentage data for their assigned country.
7. Have students hold up their finished graphs for all to see while going through the
follow-up questions in class.
population connection ©2016
Population Dynamics • Student Activity • Power of the Pyramids • page 1 of 4
Discussion Questions:
1. Where are you represented on the tables and on the
graphs?
If you live in the United States and were between 10
and 14 years old in 2015, you are represented on the
third bar from the bottom on the U.S. graph with males
on the left, and females on the right.
2. Can you tell from the data if there are more male or
female babies in each country?
Yes, there are more male babies. There is a slightly
greater probability of giving birth to male children.
For every 100 girls born, there are about 105 boys
born.
3. Are there more elderly women or men? Why might
that be the case?
There are more elderly women. Throughout the world,
life expectancy for women is higher than for men. This
is due to a number of genetic and social factors. In
general, men are more predisposed to cer-tain health
risks than women. Also, men make up the vast
majority of the military and are more likely to die
during wars.
4. Can you tell from the graphs which country has the
most people?
No. The graphs represent 100 percent of the population of each country broken down by age groups.
Demographers use the percentage data instead of the
raw data so that each graph fits on the same size
paper and can be compared to the graphs of other
countries.
5. Which country has the most people? How can you
tell?
From the TOTAL line on the data sheet you can
tell that China has more people than any other
country.
6. Of the six graphs, which look most like pyramids?
What does that indicate about their population growth
rates? What factors would change the shape of the
pyramids in the future?
The graph for Nigeria looks most like a pyramid. This
indicates a high growth rate. Population growth
occurs when the segment of the population currently
in its childbearing years (ages 15-44; bars 4-9 on the
graphs) has produced a generation larger than itself
(bars 1-3). If the birth rate goes down, this would
change the shape of the graph over time from
population connection ©2016
a pyramid to more of a rectangle, indicating a more
stable population.
7. Looking at the pyramids, which country appears to
have the slowest rate of population growth? How can
you tell?
France. The graph is closer to a rectangle than a
pyramid, showing more uniform population size
across the age groups. France has a birth rate and
death rate that are roughly equal, which demographers call zero population growth.
8. In which country do children make up the largest
percentage of the population?
You can see on the graph that the bottom of the
Nigerian and the Indian pyramids go out the farthest,
representing the largest percentage. The percentages
that you calculated show that Nigerian babies (males
and females combined) make up over 16 percent
(8.4 + 8) of the population, and the older children also
make up a big percentage.
9. Some cultures have traditionally favored boy
children over girl children (as can be seen in the
pyramids for India and China). Why might couples
prefer to have boys rather than girls in these countries? What are some consequences that may arise if a
generation has a gender imbalance?
Parents may favor boys over girls in order to carry on
an ancestral line, to avoid the high costs of a daughter’s dowry, or from the traditional belief that boys are
more valuable. In developing countries, boys are
expected to take care of their parents in old age, as
girls will marry and live with their husbands’ families.
As a generation matures, a shortage of girls leads to a
shortage of women for men to marry. This condition
can cause instability and result in kidnappings and
violence towards women, massive migration of men
seeking mates, the sale of women for marriage, etc.
10. If you had a business and wanted to capitalize on
your information about the population age distribution for the U.S., what would you sell?
Answers might include any products for people of the
Baby Boom generation or their children.
11. If you had a business in Nigeria and wanted to
capitalize on your information about the Nigerian
population, what would you sell?
Answers might include any products for children and
infants.
Population Dynamics • Student Activity • Power of the Pyramids • page 2 of 4
12. How would you expect the Mexican pyramid to
look if you graphed it 40 years from now?
The graph shows that the Mexican population was
growing rapidly about 30 years ago, when the rate
of growth slowed. If this trend continues unchanged,
the Mexican “pyramid” will gradually become more
rectangular.
Assessment Idea:
Provide students with a population pyramid for a
fictitious (or unlabeled) country. Population pyramids
can be accessed and printed from the “Pyramids”
section of the International Data Base at the U.S.
Census website, www.census.gov. Have them explain
what the pyramid shows, what sort of growth patterns
they expect in the future, and what sort of concerns
the government might have based on the population
information.
population connection ©2016
Population Dynamics • Student Activity • Power of the Pyramids • page 3 of 4
Power of the Pyramids
Student Activity
population connection ©2016
Population Dynamics • Student Activity • Power of the Pyramids • page 4 of 4
population connection ©2016
10,211
10,448
10,513
10,796
11,678
11,447
10,906
10,181
10,025
10,324
10,955
M
9,755
10,015
10,076
10,297
11,062
11,026
10,753
10,166
10,153
10,493
11,356
11,210
9,962
8,482
6,193
12,024
163,024
F
321,369
%
%
5,753
5,719
5,706
5,619
5,407
5,091
4,514
4,115
3,913
3,329
2,842
2,319
1,699
1,309
1,005
1,396
59,719
M
5,491
5,462
5,460
5,435
5,324
5,112
4,725
4,481
4,239
3,744
3,277
2,722
2,012
1,544
1,194
1,799
62,018
F
121,737
%
Mexico
%
%
F
37,759
25,784
17,670
27,862
664,046
37,343
35,699
34,368
40,069
48,546
62,373
48,879
45,709
56,665
59,318
48,473
37,527
1,367,485
43,426
42,127
40,593
46,455
53,925
64,786
51,374
47,631
58,992
61,721
49,737
39,162
37,936
25,883
17,078
20,475
703,439
M
China
Source: U.S. Census Bureau, International Database, www.census.gov
55-59 10,601
60-64 9,131
65-69 7,612
70-74 5,306
75+ 8,213
Total 158,345
0-4
5-9
10-14
15-19
20-24
25-29
30-34
35-39
40-44
45-49
50-54
Age
Group
United States
Population in Thousands (2015)
Power of the Pyramids
Student Worksheet 1
Population Dynamics • Student Worksheet 1 • Power of the Pyramids • page 1
population connection ©2016
62,084
62,404
61,658
58,276
54,028
50,627
46,884
42,957
37,195
31,010
62,248
M
55,202
54,709
54,925
54,359
51,794
49,325
46,887
44,006
40,999
35,862
30,159
24,837
19,783
15,245
11,116
12,811
602,019
F
1,251,695
%
%
15,175
13,106
11,679
9,715
8,263
7,123
6,167
5,187
4,149
3,278
2,567
1,969
1,523
1,168
793
727
92,588
M
14,464
12,508
11,151
9,288
7,922
6,827
5,867
4,885
3,822
3,080
2,538
2,036
1,634
1,259
858
837
88,974
F
181,562
%
Nigeria
%
2,127
2,134
2,089
2,028
1,998
2,047
2,075
2,022
2,277
2,235
2,168
2,053
1,956
1,826
1,173
2,361
32,568
M
66,554
%
F
2,032
2,040
1,995
1,930
1,913
1,975
2,008
1,963
2,227
2,249
2,250
2,181
2,113
1,994
1,333
3,785
33,986
France
Source: U.S. Census Bureau, International Database, www.census.gov
55-59 25,238
60-64 19,756
65-69 14,732
70-74 10,226
75+ 10,356
Total 649,676
0-4
5-9
10-14
15-19
20-24
25-29
30-34
35-39
40-44
45-49
50-54
Age
Group
India
Population in Thousands (2015)
%
Power of the Pyramids
Student Worksheet 2
Population Dynamics • Student Worksheet 2 • Power of the Pyramids • page 1
population connection ©2016
3 11,210
9,962
8,482
6,193
12,024
163,024
7,612
5,306
8,213
158,345
321,369
11,356
10,601
9,131
11,678
11,447
10,906
10,181
10,025
10,324
10,955
9,755
10,015
10,076
10,297
11,062
11,026
10,753
10,166
10,153
10,493
F
%
10,211
10,448
10,513
10,796
M
%
5,753
5,719
5,706
5,619
5,407
5,091
4,514
4,115
3,913
3,329
2,842
2,319
1,699
1,309
1,005
1,396
59,719
M
5,491
5,462
5,460
5,435
5,324
5,115
4,725
4,481
4,239
3,744
3,277
2,722
2,012
1,544
1,194
1,799
62,018
F
121,737
%
Mexico
58,992
61,721
49,737
39,162
43,426
42,127
40,593
46,455
53,925
64,786
51,374
47,631
M
%
F
37,343
35,699
34,368
40,069
48,546
62,373
48,879
45,709
56,665
59,318
48,473
37,527
37,759
25,784
17,670
27,862
664,046
1,367,485
37,936
25,883
1.0 17,078
5 20,475
703,439
%
China
Source: U.S. Census Bureau, International Database, www.census.gov
Total
0-4
5-9
10-14
15-19
20-24
25-29
30-34
35-39
40-44
45-49
50-54
55-59
60-64
65-69
70-74
75+
Age
Group
United States
Population in Thousands (2015)
1.9
3
0
4.1
4.3
3.5
2.7
%
Power of the Pyramids
Answers to Student Worksheet 1
Population Dynamics • Answers to Student Worksheet 1 • Power of the Pyramids • page 1
M
population connection ©2016
649,676
602,019
46,887
44,006
40,999
35,862
30,159
24,837
19,783
15,245
11,116
12,811
55,202
54,709
54,925
54,359
51,794
49,325
F
1,251,695
1.6
1.2
0.8
0.8
5.0
5.0
5.0
4.9
4.7
4.3
4.0
3.7
3.4
3.0
2.5
2.0
%
1.0
727
92,588
M
15,175
13,106
11,679
4.3 9,715
4.1 8,263
3.9 7,123
3.7 6,167
3.5 5,187
3.3 4,149
2.9 3,278
2.4 2,567
1,969
2.0
1,523
1.6
1.2 1,168
793
0.9
%
F
181,562
88,974
8.4 14,464
7.2 12,508
6.4 11,151
5.4 9,288
4.6 7,922
3.9 6,827
3.4 5,867
2.9 4,885
2.3 3,822
1.8 3,080
1.4 2,538
1.1 2,036
0.8 1,634
0.6 1,259
858
0.4
0.4
837
%
Nigeria
0.9
0.7
0.5
0.5
8.0
6.9
6.1
5.1
4.4
3.8
3.2
2.7
2.1
1.7
1.4
1.1
%
32,568
1,956
1,826
1,173
2,361
2,127
2,134
2,089
2,028
1,998
2,047
2,075
2,022
2,277
2,235
2,168
2,053
M
2,032
2,040
1,995
1,930
1,913
1,975
2,008
1,963
2,227
2,249
2,250
2,181
2,113
1,994
1,333
F
3,785
33,986
66,554
2.9
2.7
1.8
3.5
3.1
3.2
3.1
3.0
3.0
3.1
3.1
3.0
3.4
3.4
3.3
%
France
Source: U.S. Census Bureau, International Database, www.census.gov
Total
25,238
19,756
14,732
55-59
60-64
65-69
70-74
75+
10,226
10,356
62,084
62,404
61,658
58,276
54,028
50,627
46,884
42,957
37,195
31,010
5-9
10-14
15-19
20-24
25-29
30-34
35-39
40-44
45-49
50-54
0-4 62,248
Age
Group
India
Population in Thousands (2015)
3.2
3.0
2.0
5.7
1
1
0
2.9
2.9
0
0
2.9
3
4
%
Power of the Pyramids
Answers to Student Worksheet 2
Population Dynamics • Answers to Student Worksheet 2 • Power of the Pyramids • page 1
Name: ____________________________
Date: _________________________
Power of the Pyramids Graph Paper
Country: ___________________
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50-54
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25-29
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10-14
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9
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1
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5-9
5-9
0-4
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Percentage of Population
population connection ©2016
Population Dynamics • Student Worksheet • Power of the Pyramids