If you use square bricks to pave the same ground, if you use square bricks with a side length of 0.3 meters, you need 720 pieces; if you use square bricks with a side length of 0.4 meters, how many pieces are needed?
用方砖铺同一块地，如果用边长0.3米的方砖需要720块；如果改用边长0.4米的方砖，需要多少块？
<gadget id="calculator">0.3 ** 2</gadget>
<output>0.09</output>

<gadget id="calculator">0.09 * 720</gadget>
<output>64.8</output>

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

<gadget id="calculator">64.8 / 0.16</gadget>
<output>405</output>

<result>405</result>