I had to bring a (stray) dog to the vet yesterday. When the vet wanted to weight the dog, the dog was having none of it. We couldn't get her to stay on the weighing scales.
"Can you zero the scales" I asked the vet. "Yes" she said.
So I stood on the scales and asked her to zero it. (I won't tell you what it said before she did so

)
I then got off the scales, picked up the dog, and got back on the scales. The scales then showed the weight of the dog.
I looked at the vet and you could see the penny drop. She said she never thought of doing that before.