776. You need four tiles for one square foot (tiles are 36 square inches, a square foot is 144 square inches) so 4 tiles times 194 sqft is 776. You will want some spares too.
If that is 2' x 4' it would cover 800 square feet. If it is 2" x 4" it would cover about 5.5 square feet.
Assuming that 12 x 12 is 12" x 12" (one square foot), then 30 one-square-foot tiles would cover 30 square feet.
6' x 9' (54 square feet) = 6 square yards of tiles needed.
80
80 if the tiles are 12x12 - 12x12 is one square foot covering 80 you would need 80 tiles
Tiles that are two feet on a side cover 4 square feet. 378 of them cover 1512 square feet.
500/1.78 = 281 tiles
.375
If the tiles are 1 foot squares, it will take 1,650 of them to cover 1,650 square feet. If the tiles are 16 inch square (1-1/3 square feet, each), then it would take 1,238 tiles.
192 tiles
If that is 2' x 4' it would cover 800 square feet. If it is 2" x 4" it would cover about 5.5 square feet.
Approximately 73 square feet.
76.6 tiles
67 tiles.
Since a 12x12 tile is one square foot, then 38 12x12 tiles will cover 38 square feet.
Two tiles will suffice since they will cover 36 square feet.
I'm going to assume that the tiles are square inches, rather than square feet. But they can be converted to 3 square feet, which means 70 of them would cover the space if it were perfectly rectangular. Get 80 to be safe.