[throwaway99113]

It is sometimes used in grocery stores in Norway when you need to ask for a quantity of something that is not pre-packed.

"I'd like 2 hecto ham" means 2 hectograms (200g, or 0.2kg)

It may sound strange if you are not used to it. I also have a feeling that the younger generations prefer just measuring in grams when it is less than a kg. Let's blame the school system ;-)

We also sometimes measure area as "dekar" (1000 sq m) and "hektar" (10000 sq m)

[histories]

It's surprisingly (well) similar in italian, where "etto" is 100 g and "ettaro" is 10000 m².