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
   • Egypt moves down to light and Japan moves down to medium; the other countries stay in their classes
   • Egypt moves to light, Japan to medium and China to light, because 150 is close to the new lower line
   • Japan moves down to medium, but Egypt stays medium, because 115 is close to the old line of 50
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
   • That the map is wrong, because a map that puts two different densities into one class cannot be trusted
   • 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
5. 3.

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

6. 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.

7. 4.

   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 20 per km², the same as the region as a whole, in the light class
   • About 2 per km², 10,000 people over 4,900 km², in the light class, far below the region's 20
8. 5.

   Ren wants a map showing that Region R's people are concentrated while Region S's are spread evenly. Which map shows that?

   • A flow map, because arrows would show people moving into the city from the rest of Region R
   • A choropleth with more classes, because finer classes would give R's city its own dark shade
   • A reference map, because the city and the borders of both regions would be drawn on it
   • A dot map, where R's dots pile up in the city and S's spread across its 1,000 km²
9. 6.

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

   • A medium city and a light remainder, because 900 people per km² falls in the medium class
   • A dark city of about 900 per km² and a light remainder of about 2, a pattern one light shade hid
   • That the region's density is really 900 per km², so the first map was simply wrong
   • Two units of 50 per km² each, because splitting the region halves the density in each part
10. 7.

    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?

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

11. 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.

13. 8.

    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
    • From 2.2 (Mongolia) to 37 (the United States), about a 17-fold spread inside one class
    • About a 2-fold spread, because 37 is double the 4.6 of Canada and the others are similar
14. 9.

    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 8.

    • Eight of the 11, so the map would show little difference among most countries
    • Ten, because Bangladesh is the one country above 880 and the other ten share the two lower classes
    • Seven, the countries under 200, because the old medium line of 200 is the edge of the low group
    • Five, the countries under 50, because those are the ones the old light class held
15. 10.

    Tala writes: "Mongolia (2.2 per km²) has almost no people anywhere." What is the best correction using Card C?

    Use the picture in question 8.

    • The note is wrong, because Mongolia is in the light class with the United States, which has many cities
    • 2.2 per km² is an average, which says people are few overall but not where; towns can hold many
    • The note cannot be judged, because a density is a rate and a rate says nothing about how many people live there
    • The note is right, because a density of 2.2 per km² means about two people stand on each square kilometer