To draw a circle with a circumference of 15.7 meters, what is the distance between the two feet of the compass in decimeters?
要画一个周长是15.7米的圆，圆规两脚间的距离应取多少分米．
<gadget id="calculator">15.7 * 10</gadget>
<output>157</output>

<gadget id="calculator">2 * 3.14</gadget>
<output>6.28</output>

<gadget id="calculator">157 / 6.28</gadget>
<output>25</output>

<result>25</result>