Drag and drop countries around the map to compare their relative size. Is Greenland really as big as all of Africa? You may be surprised at what you find! A great tool for educators.
The Mercator projection is distorted.. a lot. This website will help you find the "true size" of any country by entering the name and then dragging it size around. In the example below I used Belgium since.. well, I live there.
Greenland is also a fun one to play around with, it looks MASSIVE on a normal map, then you drag it down to South America and well.. see for yourself: