As you place rooms in a project, you can use tags that sequentially number the rooms. The tags automatically number based on the Number parameter for rooms. Values can be alphabetical, numerical, or alphanumeric sequences.
Room & Area panel
To select the room, move the cursor near the center of the room until a large X appears. This X indicates the room boundaries. When you click the X, the room is highlighted in transparent blue, indicating that it is selected.
All subsequent rooms are numbered sequentially.