Choose the right map, and see what each projection distorts
Grade 9 Social Studies Worksheet
Circle the best answer.
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.
Jun moves Card C's class breaks to 120 and 400 per km². Which countries change class?
- Egypt moves down to light and Japan moves down to medium; the other countries stay in their classes
- 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
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 are more than twice as dense as each other at most, since the highest is 1,317 and 2 x 484 is 968
- 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
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 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
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.
Zee shades Valmar's Region R by its average density. What does the choropleth hide?
- That the region's density is really 100 per km², because 100,000 people live in the region
- Most people crowd into a 100 km² city of about 900 per km², hidden by the region's light shade of 20
- That Region R belongs in the dark class, because 90,000 people live in one place
- Nothing, because a choropleth is built from the region's total and the total of 100,000 people is exact
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
Esme redraws Region R as two units, the city and the land outside it. What does the new choropleth show?
- Two units of 50 per km² each, because splitting the region halves the density in each part
- 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
- A medium city and a light remainder, because 900 people per km² falls in the medium class
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?
- Five dots in each, because the region has two parts and the dots are shared between them
- Ninety dots in the city and ten outside, because each dot on the map stands for 1,000 people
- Ten dots in the city, since the region holds 100,000 people and the city is its center
- Nine dots packed into the 100 km² city and one dot on the other 4,900 km²
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.
Ari looks at the light class (under 50) on Card C. How wide a spread of densities sits inside it?
- 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
- From 0 to 50, because a class covers the values between its two lines, so its spread is 50
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.
- Five, the countries under 50, because those are the ones the old light class held
- 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
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 cannot be judged, because a density is a rate and a rate says nothing about how many people live there
- 2.2 per km² is an average, which says people are few overall but not where; towns can hold many
- The note is right, because a density of 2.2 per km² means about two people stand on each square kilometer
- The note is wrong, because Mongolia is in the light class with the United States, which has many cities
