I've decided that floor scales that you get for your bathroom are crap, especially cheap ones.
This morning I hopped on and it said "160.0". I was like, "Heh, I WISH". Slid it to another tile and hopped on it again. Same reading. Slid it to another, 190.5. That's (unfortunately) more like it.
Sometimes you can get 3 different weights. And we have another one down in the kitchen that never agrees with the one in the bathroom. I feel like I need to weigh myself 3x on each one and average it.