Choose the right map, and see what each projection distorts

Grade 9 Social Studies Worksheet

Circle the best answer.

1. Read this first

   Use this

   Note: a choropleth gives one color to a whole country, so it hides differences inside it, such as crowded cities and empty land.

3. 1.

   Jun moves Card C's class breaks to 120 and 400 per km². Which countries change class?

   • Egypt, China and Japan move, because each value lies near one of the new lines
   • Japan moves down to medium, but Egypt stays medium, because 115 is close to the old line of 50
   • Egypt moves to light, Japan to medium and China to light, because 150 is close to the new lower line
   • Egypt moves down to light and Japan moves down to medium; the other countries stay in their classes
4. 2.

   Pia sees Bangladesh (1,317) and the Netherlands (531) in the same dark class. What does the shading hide?

   Use the picture in question 1.

   • That the Netherlands is denser, because its dark shade is the one nearest to the 200 line
   • Both shade dark, hiding that Bangladesh is about two and a half times as dense as the Netherlands
   • Nothing, because two countries in the same class have the same density to within a few people
   • That the map is wrong, because a map that puts two different densities into one class cannot be trusted
5. 3.

   Bo looks at the dark class (over 200) on Card C. Which statement about the countries in it is fair?

   Use the picture in question 1.

   • Dark countries run from 200 to 484, because 200 is the lower line and India is the last dark country
   • Dark countries have about the same density, because a class groups together places that are alike
   • Dark countries here run from 342 to 1,317 per km², nearly a four-fold spread inside one class
   • Dark countries are more than twice as dense as each other at most, since the highest is 1,317 and 2 x 484 is 968
6. 4.

   Milo compares Canada (4.6) and Australia (3.5) on Card C. Which statement about the difference is right?

   Use the picture in question 1.

   • Canada is about 31% denser than Australia, while Australia is about 24% less dense than Canada
   • Canada is about 24% denser than Australia, and Australia is about 31% less dense than Canada
   • Canada is clearly the denser country in practice, because the table gives its density as the larger number
   • Canada is about 1% denser, because the difference is 1.1 people per km² and the map's classes are 50 wide

7. Use this

   Card D (made up for practice). The country of Valmar has two regions. Region R covers 5,000 km² and holds 100,000 people; 90,000 of them live in one city that covers 100 km², and the other 10,000 live on the remaining 4,900 km². Region S covers 1,000 km² and holds 100,000 people spread evenly. Choropleth key: light under 50 people per km²; medium 50 to 200; dark over 200. Dot map key: one dot = 10,000 people.

8. 5.

   Zee shades Valmar's Region R by its average density. What does the choropleth hide?

   • Nothing, because a choropleth is built from the region's total and the total of 100,000 people is exact
   • That the region's density is really 100 per km², because 100,000 people live in the region
   • That Region R belongs in the dark class, because 90,000 people live in one place
   • Most people crowd into a 100 km² city of about 900 per km², hidden by the region's light shade of 20
9. 6.

   Kira works out Valmar's Region R outside the city. What density does that land have, and in which class?

   • About 100 per km², 10,000 people over the 100 km² of the city, in the medium class
   • About 900 per km², the same as the city, in the dark class, since the region is one unit
   • About 2 per km², 10,000 people over 4,900 km², in the light class, far below the region's 20
   • About 20 per km², the same as the region as a whole, in the light class
10. 7.

    Esme redraws Region R as two units, the city and the land outside it. What does the new choropleth show?

    • That the region's density is really 900 per km², so the first map was simply wrong
    • A dark city of about 900 per km² and a light remainder of about 2, a pattern one light shade hid
    • A medium city and a light remainder, because 900 people per km² falls in the medium class
    • Two units of 50 per km² each, because splitting the region halves the density in each part
11. 8.

    Noah draws Valmar's Region R on a dot map (one dot = 10,000 people). How many dots sit in the city, and how many outside?

    • Ninety dots in the city and ten outside, because each dot on the map stands for 1,000 people
    • Nine dots packed into the 100 km² city and one dot on the other 4,900 km²
    • Five dots in each, because the region has two parts and the dots are shared between them
    • Ten dots in the city, since the region holds 100,000 people and the city is its center

12. Use this

    Note: a choropleth gives one color to a whole country, so it hides differences inside it, such as crowded cities and empty land.

14. 9.

    Ari looks at the light class (under 50) on Card C. How wide a spread of densities sits inside it?

    • From 0 to 50, because a class covers the values between its two lines, so its spread is 50
    • Little spread, because the light class sits under 50 and its countries are nearly empty
    • About a 2-fold spread, because 37 is double the 4.6 of Canada and the others are similar
    • From 2.2 (Mongolia) to 37 (the United States), about a 17-fold spread inside one class
15. 10.

    Luz swaps Card C's classes for three equal-width classes over 0 to 1,320. How many of the 11 countries fall in the lowest class (0 to 440)?

    Use the picture in question 9.

    • Seven, the countries under 200, because the old medium line of 200 is the edge of the low group
    • Eight of the 11, so the map would show little difference among most countries
    • Five, the countries under 50, because those are the ones the old light class held
    • Ten, because Bangladesh is the one country above 880 and the other ten share the two lower classes