During the summer vacation, the school plans to use square bricks to pave the corridors. If square bricks with an area of 9 square decimeters are used, 480 bricks are needed. If square bricks with a side length of 4 decimeters are used instead, how many bricks are needed? (Solve with ratio)
暑假期间，学校准备用方砖铺走廊，如果用面积是9平方分米的方砖，需要480块，如果改用边长是4分米的方砖，需要多少块？(用比例解)
<gadget id="calculator">480 * 9</gadget>
<output>4_320</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">4_320 / 16</gadget>
<output>270</output>

<result>270</result>