I have a digital scale that I bought at WalMart - it was $35.
I like it because it does read "points" (168.2) but I only record the whole numbers (so I'm "168").
I weigh several times a day at different times, just to get a feel for what my body is actually DOING with all that food, water, & waste.
I weigh 1st thing in the morning, after potty, completely naked.
I weigh again about an hour later, after I've had breakfast, before getting dressed. I usually see anywhere from .2 to 1.2 pound difference.
Then I weigh again when I get home, after exercise, and before bedtime.
I can see anywhere from a +.5 to a 2.5 weight gain.
Then the next day, I'm down again, sometimes -1 or -2 pounds.
After eating "fun" for Memorial Day 4-day weekend (two cook-outs, etc.) I went from 168 on Friday to 173 on Tuesday morning. Then after MD4-day weekend, I got right back on plan, & I was back down to 168 by yesterday, so, according to the scale, I gained 5 pounds in 4 days, and then I lost 5 pounds in 6 days.
Now... I KNOW I didn't gain 5 pounds of fat in 4 days, and I certainly didn't lose 5 lbs of fat in 6 days. No way!
I couldn't have possibly eaten THAT MANY EXTRA calories, or a deficit of that many less calories in so little time. One has to take into consideration the water weight & the sheer volume of weight of the food intake or output.
My scale isn't fickle & it's not dumb either - it's a good scale!
... my weight fluctuates throughout the day, every day. I use the 1st morning weigh-in as my "true weight" and that's what I log on my 3FC ticker.