Would appreciate if someone could check my work...

I want to put a tile border around a swimming pool that is 9’ x 12’. The tiles are 6” x 6” square. How many tiles will I need?

This is what I did:
Area of the pool: 9 x 12 = 108 feet squared
Area of the tile = .5 sq ft

Divide 108/.5 = 216
Add 4 for the 4 corners

So I will need 220 tiles total

If one side of a tile = 6", then the area of the tile = 6" * 6" = 36" = 3 sq feet.

So what do I do from there....divide by 3 instead of .5?