In order to beautify the environment, the school uses colored cement bricks to pave the road. It takes 3,600 pieces to pave with square bricks with a side length of 2 decimeters. If it is replaced with 9 square decimeters, how many pieces are needed? (Solution by ratio).
学校为了美化环境，用彩色水泥砖铺路面，用边长2分米的方砖铺需3600块，若改用9平方分米的方砖铺，需要多少块？(用比例解)．
<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">4 * 3_600</gadget>
<output>14_400</output>

<gadget id="calculator">14_400 / 9</gadget>
<output>1_600</output>

<result>1_600</result>