Seeming paradox when squaring distance depending on units

Hello all



This is probably simple and I'm overlooking something



1 mile = 5280 feet



10% of a mile is 528 feet



528 feet squared is 278,784 feet which is 52.8 miles squared



But 0.1 miles squared is .01 miles squared



So depending on if you square it as 0.1 miles, or if you convert it to feet, then square it and convert it back, you get wildly different answers



Why is this.? Not sure why I thought of this.



Thanks in advance