I have played with a couple of Digital Scales now. My wife decided to get a real fancy one for her Kitchen, (What else who you expect from a retired engineer) and found that her reading seem to differ by the phase of the moon! the lower accuracy one she used to measure the Dog's Food tends to drift for about 20 minutes when started up and so she leaves it on all the time. I have a similar one to the "dog food" scale for my Darkroom.

All three are from "My Weigh"

Note that the electronic scales are calibrated by putting a SPECIFIC amount to weights on the scale. When I bought my first one I only bought one of the weights thinking that it was just used as a check, so had to go back and buy another weight. Order the set that the scale you buy needs at the start.