I like to cook with a scale. Normally, to weigh out an amount, I place an empty vessel on the scale, zero the scale, and then add the thing I want to weigh. But sometimes I want to know how much of an ingredient or mixture is in a container already, like when I want to split a batter in half for two pans or something.
To avoid the situation of having a mixture in a container without an appropriately-zeroed scale, I have preemptively collected the masses of all the cooking vessels I regularly use.