A small road is paved with square bricks with a side length of 0.3 meters, and 2400 pieces are needed. If it is paved with square bricks with a side length of 0.4 meters, how many square bricks are needed? (Solution with proportional knowledge)
一条小路，用边长0.3米的方砖铺地，需要2400块，如果改用边长为0.4米的方砖铺，需要多少块方砖？(用比例知识解)
<gadget id="calculator">0.3 ** 2</gadget>
<output>0.09</output>

<gadget id="calculator">0.09 * 2_400</gadget>
<output>216</output>

<gadget id="calculator">0.4 ** 2</gadget>
<output>0.16</output>

<gadget id="calculator">216 / 0.16</gadget>
<output>1_350</output>

<result>1_350</result>