If the floor of a living room is paved with square floor tiles with a side length of 0.3 meters, 640 pieces are needed. If the floor is paved with square floor tiles with a side length of 0.4 meters, how many pieces are needed? (Solve with ratio)
一间会客厅地面用边长0.3米的正方形地砖铺，需要640块，如果改用边长是0.4米的正方形地砖铺，需要多少块？(用比例解)
<gadget id="calculator">0.3 * 0.3</gadget>
<output>0.09</output>

<gadget id="calculator">0.4 * 0.4</gadget>
<output>0.16</output>

<gadget id="calculator">640 / 0.16</gadget>
<output>4_000</output>

<gadget id="calculator">0.09 * 4_000</gadget>
<output>360</output>

<result>360</result>