Austrians buy food (sausage, cheese, etc) by decagrams, and also use them in kitchen recipes. They call them simply “Deka” (in German), omitting the “grams” (-gramm).
I assume you have a different notion of the whole of Europe than I have. ☺ Certainly yours is more universal, since there are a couple of European countries I haven't been to.
Americans be like wHaTs A dEcAmEtRe XD Niqqa it's literally 10 metres. You just add a prefix on the main unit and you get multiples and submultiples. Here's some of the multiples: Deca = 10 (from greek δέκα, déka, "ten"), Hecto = 100 (from εκατόν, ekatón, "one hundred"), Kilo = 1000 (from χίλιοι, khíloi, one thousand; that's why you write 1K), Mega = 1000000 (1M), Giga = 1 billion (as in GB, gigabyte, that's a billion bytes) and many more after this that are not really that important.