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.

   Ren reads Card A. Which pyramid has the widest base, and what does that suggest?

   • The United States': a column is wide at the bottom, so it has the widest base of the three
   • Japan's: its wide top shows many young people, which suggests a high birth rate there as well
   • Niger's: 47.0% are aged 0–14, far more than the others, which suggests a high birth rate there
   • Niger's: 47.0% are aged 0–14, which shows its birth rate will stay high in the years to come
3. 2.

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

   • Expansive: a wide top means the population is growing quickly, because many older people are alive
   • 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
4. 3.

   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?

   • Constrictive: the older share, 17.4%, is large, so the top is wider than the base
   • 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
   • Expansive: 17.6% aged 0–14 is a larger share than Japan's 11.6%, so its base is wide, as Niger's is
5. 4.

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

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

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

   • 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 53%, since 100 minus 47 is the share aged 15–64 and the older ones are counted among them
   • About 50%, since the three shares add to 100 and 100 minus 47.0 minus 2.6 is 50.4
7. 6.

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

   • A wide base means many older people are alive, and their long lives raise the number of births
   • A wide base means each woman has the same number of children, and the births per woman follow from it
   • A wide base means children are counted twice, so the birth rate is double what it would otherwise be
   • A wide base means many young people, and they were born in recent years, so births have been high
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 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
   • 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
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 population is growing by 47% a year, since 47.0% of people are children and children are growth
    • Niger has 47 births for each 100 women, since 47.0% is the share aged 0–14 in the pyramid
    • 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
11. 10.

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

    • The United States, since 17.4% aged 65+ is almost as much as the 17.6% aged 0–14 and so is larger
    • Both Japan and the United States, since each has a top that is at least as wide as its base
    • 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