It's not a silly question, I wondered the same when I started
This might be a little alien to you, but I think of my weight in two forms: stones & lbs, and just lbs. Example: right now I'm at 229lbs, which is 16st 5lbs. (14lbs to a stone). My mini goal is to get under 16st, which will take me to 223lbs. Then my next mini goal will be to get under 220, then I'll be shooting to get to 15st (210).
Sorry if that's far too confusing for you, but it's how I do it!