How do these work???

[Farjo]

Ah, so if someone wanted 3&ahalf kilo you could put three 1kg weights on one plate then the other side (the goods) will be 3.5kg when the scale reaches 500g. Is that what you mean?

And yes I see what you mean about the place for a bowl and the other plate for cheese etc. I guess the bowl would have come with it and was the exact weight to take the scale to 0 (zero grams). Although perhaps that sounds a bit tricky, mechanically.