On a rectangular plank with a length of 1 meter and a width of 0.8 meters, the largest pot cover is to be sawn. What percentage is the utilization rate of this plank?
在一块长1米，宽0.8米的长方形木板上要锯一块最大的锅盖，这块木板的利用率是百分之几？
<gadget id="calculator">0.8 / 2</gadget>
<output>0.4</output>

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

<gadget id="calculator">1 * 0.8</gadget>
<output>0.8</output>

<gadget id="calculator">0.16 / 0.8</gadget>
<output>0.2</output>

<gadget id="calculator">3.14 * 0.2</gadget>
<output>0.628</output>

<result>0.628</result>