IMO conversions between weight, volume and dimensions are very useful for the average person, too. At least when the average person cooks food, builds something

IMO conversions between weight, volume and dimensions are very useful for the average person, too. At least when the average person cooks food, builds something, etc. Though obviously this one-to-one conversion of weight/volume only works so great if you're dealing with water or other substances with a a similar density. But even so, also knowing that granite has density that is 2.7 times that of water helps e.g. in estimating how much a rock weighs. I'm in a country that is as metric as it can get, and I'm still infuriated enough about package sizes that are sometimes multiples of imperial units, even if expressed in metric units. "Mix 210 g of couscous to 2.4 dl of boiling water". Absurd. Well, recently they changed it to a more usable "Mix 2 dl of couscous to 2.5 dl of boiling water." That is a lot better. I usually don't want to use a kitchen scale and want to get away with a measuring cup.