A rope is 6.28 meters long and is wound around the trunk exactly 10 times. What is the approximate cross-sectional area of the trunk?
一根绳子长6.28米，在树干上正好绕了10圈．树干的横截面积大约是多少？
<gadget id="calculator">6.28 / 10</gadget>
<output>0.628</output>

<gadget id="calculator">0.628 / 3.14 / 2</gadget>
<output>0.1</output>

<gadget id="calculator">0.1 ** 2</gadget>
<output>0.01</output>

<gadget id="calculator">3.14 * 0.01</gadget>
<output>0.0314</output>

<result>0.0314</result>