Read population pyramids

Grade 9 Social Studies Worksheet - Building Confidence

Circle the best answer.

1. Read this first

   Use this

   Card A, three population pyramids, 2023 (UN estimates, World Bank), in words. Niger: a very wide base that narrows quickly; 47.0% of people are aged 0–14 and 2.6% are 65 or older. Japan: a narrow base and a wide top; 11.6% are aged 0–14 and 29.6% are 65 or older. United States: closer to a column; 17.6% are aged 0–14 and 17.4% are 65 or older. Card B, key and notes: each bar is an age group, youngest at the bottom; males are on the left and females on the right; bar length is the share of the population. A broad base means a high share of young people, which suggests a high birth rate. An expansive pyramid has a wide base, a constrictive pyramid a narrow base, and a stationary pyramid about the same width from bottom to top; in a stationary population, births and deaths roughly balance. The age shares of a country add to 100%.

2. 1.

   Japan's pyramid has a narrow base and a wide top. What type is it, and why, Tala asks?

   • Constrictive: a narrow base means few young people, 11.6%, next to many older people, 29.6%
   • Expansive: 29.6% is a larger share than 11.6%, and a larger share at either end makes it expansive
   • Stationary: a base and a top of different widths are what make a pyramid stationary and steady
   • Expansive: a wide top means the population is growing quickly, because many older people are alive
3. 2.

   The United States pyramid is closer to a column, with 17.6% aged 0–14 and 17.4% aged 65+. Which type is it, Zee asks?

   • It is not any of the three types, since a column has no wide part and so has no type
   • Stationary: the base and top are about the same width, at 17.6% and 17.4%, so it is close to a column
   • Constrictive: the older share, 17.4%, is large, so the top is wider than the base
   • Expansive: 17.6% aged 0–14 is a larger share than Japan's 11.6%, so its base is wide, as Niger's is
4. 3.

   In Japan, how do the shares aged 65+ and aged 0–14 compare, using Card A, Bo asks?

   • Young people outnumber older people, since the young belong to the base of the pyramid and the base is wide
   • Older people outnumber young people about 2.5 to 1, since 29.6% is about 2.5 times 11.6%
   • Older people outnumber young people about 5 to 1, since 29.6 is about 5 times the 6 that is left over
   • They are about equal, since both are shares of one population and the two shares must therefore balance
5. 4.

   What share of Niger's people are aged 15–64, using Card A and the note that shares add to 100%, Esme asks?

   • About 53%, since 100 minus 47 is the share aged 15–64 and the older ones are counted among them
   • About 5%, since 47.0 minus 2.6 minus the rest leaves a small share in the middle ages
   • About 49.6%, since 47.0 plus 2.6 is the share that is aged 15–64 and the others are children
   • About 50%, since the three shares add to 100 and 100 minus 47.0 minus 2.6 is 50.4
6. 5.

   Why does a wide base suggest a high birth rate, Jun asks?

   • A wide base means each woman has the same number of children, and the births per woman follow from it
   • A wide base means many older people are alive, and their long lives raise the number of births
   • A wide base means many young people, and they were born in recent years, so births have been high
   • A wide base means children are counted twice, so the birth rate is double what it would otherwise be
7. 6.

   Which type is Niger's pyramid, with a very wide base that narrows quickly, Kira asks?

   • Stationary, since the narrowing is steady from bottom to top and so is the same shape throughout
   • Constrictive, since a base that narrows quickly is a constricted base
   • Expansive, since Niger's base is very wide and a pyramid with a wide base is called expansive
   • Expansive, since the older share is large, 2.6%, and a larger top makes it expansive in shape
8. 7.

   Card B says births and deaths roughly balance in a stationary population. What does that mean for the United States pyramid, Luz asks?

   • Its column shape shows the population cannot change, since a stationary pyramid stays put
   • Its column shape fits births and deaths roughly in balance, so the number of young and older people is about equal
   • Its column shape fits births far above deaths, so the base is as wide as the top by growth
   • Its column shape fits deaths far above births, so the top is as wide as the base by shrinking, with the older ages piling up each year
9. 8.

   Which list puts the three countries in order from the widest base to the narrowest, using Card A, Milo asks?

   • Niger, then Japan, then the United States, since the United States is nearly a column and so is narrowest
   • Japan, then the United States, then Niger, since Japan's pyramid is widest at the top
   • Niger first at 47.0%, then the United States at 17.6%, then Japan at 11.6%
   • The United States, then Niger, then Japan, since a column is wide at the bottom and so beats a pyramid
10. 9.

    Which claim about Niger is best supported by Cards A and B, Noah asks?

    • Niger's birth rate is lower than Japan's, since Niger's pyramid has a shorter top than Japan's
    • Its wide base suggests a high birth rate, though the pyramid does not give the number of births per woman
    • Niger has 47 births for each 100 women, since 47.0% is the share aged 0–14 in the pyramid
    • Niger's population is growing by 47% a year, since 47.0% of people are children and children are growth
11. 10.

    Which country has fewer young people than older people, using Card A, Pia asks?

    • Japan, with 11.6% aged 0–14 against 29.6% aged 65+, so its older people outnumber its young
    • Niger, since just 2.6% of its people are aged 65+ and that small share is a narrow top
    • Both Japan and the United States, since each has a top that is at least as wide as its base
    • The United States, since 17.4% aged 65+ is almost as much as the 17.6% aged 0–14 and so is larger