Translation:There are other pupils in the classroom
I had ''Other students are in the classroom''. Where does ''there'' come from?
Sometimes using just a -po verb indicates existence rather than just place, but since there's a place after it ... I'm inclined to agree with you that this is not the best match.
To say "There are other students" I'd start the sentence with kuna or pana or, if I wanted to emphasise the "inside-ness" of their location, then mna.
I probably wrote "The other students are in the classroom" when I came across this sentence.
I was thinking the same, since it's inside the classroom. First they teach us how things that are inside something have to go with mna/wamo, and they teach us that we have to use pana for "there is" , and wapo for "something is somewhere", and here they happily breaks both of the rules