Each 16 in * 16 in tile covers 11/3 * 11/3 square feet = 16/9 sq feet. Area to be covered = 12*12 = 144 square feet. So number of tiles required = 144/(9/16) = 144*16/9 = 81 tiles.

One square foot can be divided into four 6 inch squares. Multiplying the number of square feet by 4 gives an answer of 4,000 6 inch squares in an area of 1,000 square feet.