The sun has a diameter of 1,391,980 kilometers, 109 times as big as the Earth. 
The moon has a diameter 3,475 kilometers, a quarter that of the Earth, 1/436th that of the sun. 
And yet, in our sky, they are exactly the same size.*
Solar eclipse, November 13, 2012
What’s it mean?
*Thanks to David Grinspoon for this observation in Lonely Planets.