A rope with a length of 12.56 meters goes around a tree trunk exactly 10 times. What is the diameter of the cross section of the tree trunk?
一根长12.56米的绳子正好绕一树干10周，树干横截面的直径是多少？
<gadget id="calculator">12.56 / 10</gadget>
<output>1.256</output>

<gadget id="calculator">1.256 / 3.14</gadget>
<output>0.4</output>

<result>0.4</result>