Excellent question, but let's rephrase it.
Suppose you have a square of surface area of 2851.
What would be a hundredth of such square?
What would be surface area of that hundredth.
Why hundredth? Because percent denotes hundredths cent is a latin word for hundred. You would usually encounter similar word that describes 100 years: century.
Well it is actually very easy. Just divide 2851 into 100 pieces and look at what is the area of one piece.
So a single piece has an area of 258.1.
Hope this helps. :)