Maps and Data
Learn
Maps do more than show where places are. They can also show data, which is information about those places. In this lesson, you will learn how maps use colors, symbols, and keys to share information.
What Is Data on a Map?
Data is information we can count or measure. Maps can show data like:
- How many people live in a place (population)
- What the weather is like (temperature, rain)
- What animals live there
- What crops farmers grow
Map Keys and Legends
A map key (also called a legend) explains what the colors and symbols mean. Always look at the key first to understand what the map is showing you.
Types of Data Maps
Here are some common ways maps show data:
- Color Maps: Different colors show different amounts. Dark colors often mean "more" and light colors mean "less."
- Symbol Maps: Small pictures or dots show where things are. More dots mean more of that thing.
- Picture Maps: Tiny drawings show what is found in each place, like trees for forests or cows for farms.
Reading Numbers on Maps
Some maps use numbers to show exact amounts. You might see:
- Numbers inside each state or country
- A scale that shows what each color or size means
- Labels that tell you the data for each place
Comparing Data on Maps
Maps help us compare places quickly. By looking at colors or symbols, we can answer questions like:
- Which continent has the most deserts?
- Where do more people live - in the mountains or near the ocean?
- Which country grows the most wheat?
Examples
Example 1: Reading a Color Map
Map: A world map where dark green = many trees, light green = some trees, yellow = few trees, tan = desert.
Question: Which continent has the most forests?
How to solve: Look for dark green areas. South America has a very large dark green area (the Amazon rainforest). Africa also has dark green near the middle (Congo rainforest).
Answer: South America has one of the largest forest areas in the world.
Example 2: Using a Map Key
Map Key:
- Blue star = Capital city
- Red dot = Large city
- Small black dot = Small town
Question: You see a blue star labeled "Washington D.C." What does this tell you?
Answer: Washington D.C. is a capital city (the capital of the United States).
Example 3: Comparing with Symbols
Map: A map shows wheat symbols. Asia has 12 wheat symbols, Europe has 6 wheat symbols, and Africa has 3 wheat symbols.
Question: Which continent grows the most wheat?
How to solve: Count the symbols for each continent. 12 is more than 6, and 6 is more than 3.
Answer: Asia grows the most wheat.
Practice
Answer these questions to practice reading maps and data.
1. What is a map key (or legend)?
Think about: What does it explain?
2. On a color map, dark blue means "a lot of rain" and light blue means "a little rain." Which color would you look for to find the wettest places?
Think about: Dark or light?
3. A map shows animal symbols. Lions appear in Africa and tigers appear in Asia. What does this data map tell you?
Think about: Where do these animals live?
4. Why is it important to look at the map key before reading the rest of the map?
Think about: How will you know what the colors mean?
5. A population map shows: North America = 580 million, South America = 430 million. Which continent has more people?
Think about: Which number is bigger?
6. What are three types of data that maps can show?
Think about: Weather, animals, people...
7. On a map, you see orange for "hot" places and blue for "cold" places. Antarctica is colored dark blue. What does this tell you about Antarctica?
Think about: What does dark blue mean?
8. A map uses dots to show cities. Country A has 15 dots and Country B has 7 dots. Which country has more cities shown on this map?
Think about: Count the dots.
9. How can a map help you compare two continents quickly?
Think about: Colors, symbols, size...
10. You want to find where bananas grow. What kind of symbol might a map use to show this data?
Think about: A picture of what?
11. A map shows mountains in brown and flat land in green. You see mostly brown in a country. What can you say about this country's land?
Think about: What does brown represent?
12. Why might the same place be shown with different colors on different maps?
Think about: Different maps show different data.
Check Your Understanding
Test yourself with these review questions.
Question 1: What is data?
Show Answer
Data is information that we can count or measure. On maps, data can show things like population, weather, animals, or crops.
Question 2: What should you always look at first when reading a data map?
Show Answer
You should look at the map key (legend) first. It tells you what the colors and symbols on the map mean.
Question 3: Name two ways that maps can show data.
Show Answer
Maps can show data using: colors (dark vs. light), symbols (dots or pictures), and numbers. Any two of these are correct.
Question 4: How does a data map help us compare different places?
Show Answer
A data map lets us see information about many places at once. We can quickly compare by looking at colors, counting symbols, or reading numbers for each place.
Next Steps
- Find a data map in a book or online and practice reading the key
- Try to find two different data maps about the same place and compare them
- Move on to the next lesson: Claim and Evidence Writing
- Return to practice problems periodically for review