The kitchen of Xiaoli s house is 36 decimeters long and 24 decimeters wide, and they are 6 yuan a 2

Let's start with the kitchen area.

36 times 24 equals 864 square decimeters.

Then count the 2 times 2 floor tiles.

2 times 2 equals 4 square decimeters.

Then count the 3 times 3 floor tiles.

3 times 3 equals 9 square decimeters.

Divide the kitchen area by the area of the two floor tiles.

864 divided by 4 equals 216

So a 2 by 2 floor tile costs 216 pieces.

864 divided by 9 equals 96

So a 3 by 3 floor tile costs 97 pieces.

2 times 2 floor tiles cost 6 yuan.

6 times 216 equals 1296 yuan.

3 times 3 floor tiles cost 9 yuan.

97 times 9 equals 873 yuan.

1296 is greater than 873, so 9 yuan is more economical.

3 dm by 3 dm floor tiles save money.