Of course they are. I had a teacher, and classmates and did my school tasks. What else do you need to consider it an school?
The only difference is that there were no several classrooms - depending on your grade, you would sit at a table or another.
They are rural schools, for children in areas of difficult access.
I lived in a very small village (less than 100 inhabitants), so we had this school for the younger kids.
Older kids would find a way to go to the city - you just had to walk a few kilometers. And no, there was no bus or anything like that.
Those were the old times though, that kind of schools are slowly disappearing because hiring a bus is becoming more affordable.
There are still some, but they are becoming more and more rare.
Anyway, smallish schools (just not that small) are pretty common here. And people prefer them for their children, specially when they are young.