Are unit abbreviations like mm for millimetres or % for percent used in Japanese?
I've seen people translate those two words in to ミリメートル and パーセント respectively and that is what makes me raise this question.
In written Japanese the abbreviations mm, kg, km, mg, cm, ml etc. are used as early as the second year of primary school. Their correct pronunciation is ミリメートル, キログラム, キロメートル, ミリグラム, センチメートル, ミリリットル respectively. In everyday language, mm and ml are abbreviated to ミリ (although ミリグラム seems to stay as is; see comments below), kg, km are abbreviated to キロ and cm to センチ.