I don't remember a single post-Soviet school which did not do that. Sometimes your teacher gets replaced for one reason or another, but unless that happens, th

I don't remember a single post-Soviet school which did not do that. Sometimes your teacher gets replaced for one reason or another, but unless that happens, the default is that a given subject (such as maths) is taught by the same teacher from beginning (middle tier school) to the end. Students end up informally calling their teachers by the subject since threre is no ambiguity - "the geographian" or "the english".