A globe is true, but you cannot fold it into your pocket. A flat map is handy, but it has a secret: it has to stretch some places.
Key idea
A flat map is easy to carry and shows the whole world at once, but it stretches some places. A globe shows true shapes and sizes, but you see only one side at a time.
Why it works
Try to flatten an orange peel: it tears or stretches. A round Earth cannot lie flat without changing something. Many flat maps stretch the places near the North and South Poles the most.
Worked example: Greenland and Africa
On some flat maps, Greenland looks as big as Africa. Which is really bigger?
- Greenland covers about 2.2 million square kilometers.
- Africa covers about 30.4 million square kilometers.
- 30.4 ÷ 2.2 is about 14.
Answer: Africa is about 14 times bigger.
Common mistake
Many people believe Greenland is as big as Africa, because they saw it that way on a flat map. Check sizes on a globe.
For the grown-up. Peel an orange in one piece and try to press the peel flat. Talk about how a map has the same problem.