Wind a thin copper wire 62.8 meters long on a cylindrical drum, and wind it exactly 100 times. What is the diameter in meters of the cross section of this cylindrical drum?
把一根长62.8米的细铜丝，绕在一个圆柱形滚筒上，正好绕100圈．这个圆柱形滚筒横截面的直径是多少米？
<gadget id="calculator">62.8 / 100</gadget>
<output>0.628</output>

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

<result>0.2</result>