How many 20x20 inch tiles are needed for a 1372 square foot house?

Is this your homework?

Each tile is 400 square inches. That's 20 x 20 = 400

In a square foot there are 144 square inches. That's 12 x 12 = 144

In the house there are 197568 square inches. That's 1372 x 144 = 197568

So how many tiles?

Divide the house area in sq inches by tiles in sq inches.

So number of tiles is 493.92 tiles. That's 197568 / 400 = 493.92

Of course you can't buy 0.92 tiles, so call it 494 tiles.

In reality, there is a lot of wastage. No room fits tiles exactly so you have to cut them. Add on about 10% or 50 tiles for wastage.

And remember that the old fashioned Imperial system (inches, feet, yards, chains, furlongs, miles, leagues) is only used in two countries in the universe. The UK and the USA. Everybody else uses metres.