Parents are going to re-lay the floor tiles in Xiao Ming's room. Xiaoming's room is 6 meters long and 3 meters wide, but his parents want to choose square bricks with a unit price of 4 yuan and an area of 9 square decimeters. However, Xiao Ming has taken a fancy to floor tiles with a side length of 2 decimeters at a unit price of 3 yuan. Which solution is more economical?
父母准备给小明的房间重新铺地砖．小明的房间长6米，宽3米，可是父母想选择单价为4元，面积为9平方分米的方砖．小明却看中了单价为3元的边长为2分米的地砖，哪种方案更省钱呢？
<result>9</result>