Solution: first calculate the indoor floor area, and then calculate the total area of tiles for comparison. It is enough that the total area of tiles is greater than the indoor floor area, otherwise it is not enough. 8 decimeters =0.8 meters

Indoor building area = 12*6.5=78 square meters. Total tile area =0.8*0.8* 105=67.2 square meters (less than indoor building area). There are not enough tiles. Poor: 78-67.2= 1 1.2 m2, which is about 18 tiles of the same specification.