Suffix For Room Numbers
Suffix
ごうしつ
おきゃくさまのおへやは、302号室になります。
Your room is 302.
このマンションの444号室はゆうれいが出ることで有名です。
The room 444 of this apartment is known for being haunted.
102号室の坂本と申します。
I’m Sakamoto from room 102.
This is a counter that can be used after numbers to let you know what number room it is. It's a room number that you use in apartments and hotels to know exactly which room you're looking for.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.