circus monkey performs a tightrope walk on a unicycle. The diameter of the wheel is 40 centimeters. To ride a 31.4-meter steel wire, how many turns does the wheel have to turn.
马戏团小猴表演骑独轮车走钢丝，车轮的直径是40厘米，要骑过31.4米的钢丝，车轮要转动多少圈．
<gadget id="calculator">31.4 * 100</gadget>
<output>3_140</output>

<gadget id="calculator">3.14 * 40</gadget>
<output>125.6</output>

<gadget id="calculator">3_140 / 125.6</gadget>
<output>25</output>

<result>25</result>