So with the apartment bingo, they number their bingo boards with floor numbers and room numbers. The floor numbers can be anything 1-5, and the room numbers can be anything 1-5, for example 204, 105, 503, like that. There are 25 squares, so using all the combinations of those numbers will fill the board. Then I just call out floor and room numbers using ordinal numbers, i.e. fifth floor, second room, third floor, first room.