How many angels can dance on the head of a scale?

OK, I know the question is really "How many angels can dance on the head of a pin?"  But I don't have much use for pins at the moment. . .

Anyway, one of the countless people who have "Lose weight" as a New Year's Resolution was talking to me about our various progress at work this week and she was complaining about her scale.  I thought our conversation was important enough to write down . . .

Basically, we tend to think of a scale as showing a super-accurate, unvarying weight.  But I know better . . . and in fact, I know that my scale actually rounds off the weights.  So, you might ask yourself, where do the suspiciously accurate weight loss claims in this blog originate?  I figure that the trend is the thing, rather than the actual number -- that is to say, if the scale's a little off now, it probably was then.  So here's a bit on the care and feeding of MY scale.  Your results may differ.

First, confession time . . . I was a wrestler in Junior High and High School.  Wrestlers are segregated out by weight class, and weight makes a difference.  So wrestlers set a goal to get to the lowest weight they possibly can . . . and learn how to lean and shift their center of gravity to make the scale read as light as possible.  (Tip: for the old fashioned Doctor's office Scale, standing with your feet wide and pushing down hard with one foot or the other tends to make it read anywhere from 1/2 pound to 2 pounds light.)  I try to restrain these habits on my home scale. 

Second, I live in a house that was relatively cheaply built in the mid 1970's . . . so there's all sorts of soft spots in the floor.  I discovered by accident once that sliding the scale about 18 inches to the right of where we normally keep it in our bathroom will cause you to lose about 7 pounds. . . so we put the scale on the same place in the patterned tile every time.  Even with that, both my wife and I tend to weigh ourselves multiple times and try to pick the most reasonable and/or the one that the scale "settles on."  This morning, for example, I weighed four times, with a four pound swing between them.  The first was clearly unreasonable, a loss of 5 pounds since yesterday, the second showing a half pound loss, the third and fourth were equal at a pound and a half down, so that's what I recorded.

Third, as I mentioned, our scale rounds things off.  On our spreadsheet, my wife's weight frequently ends with .2 or .4 or any other even number, but never any odd numbers.  My weight, invariably, comes to either an even pound or half pound.

Finally, my home scale reads at least a little bit heavier than my doctor's scale.  Even though I'm wearing substantially less clothes on my home scale, and I weigh myself before I eat anything in the morning . . . and I'm fully clothed at the doctor's, and usually have had two meals and two snacks before I see him, plus most of a liter of water. . . I'm lighter at the doctor's office than I was that morning at home.

So you see, the weight that we record each day is a bit of an educated guess.