piece of iron wire is 628m long and is wound exactly 400 times on a round rod. What is the diameter of the cross-sectional area of the round rod in centimeters?
一根铁丝长628m，在一根圆棒上正好绕了400圈，这根圆棒的横截面积的直径是多少厘米？
<gadget id="calculator">628 / 400</gadget>
<output>157/100 = around 1.57</output>

<gadget id="calculator">100 / 3.14</gadget>
<output>31.847134</output>

<gadget id="calculator">(157/100) * 31.847134</gadget>
<output>50</output>

<result>50</result>