N4 — outside your level filter
数＋号室
Needs a numeral in front of it and takes no だ／です, so there are no forms to conjugate.
号室
goushitsuroom number ~N4counter
Example sentences2
田中様を三号室にご案内しました。
tanaka-sama o sangoushitsu ni go annai shimashita.
We showed Mr Tanaka to room 3. formal
何号室だっけ、田中さんの部屋？
nangoushitsu dakke, tanaka-san no heya?
What room number was Tanaka's room again? casual