The radius of the small circle is 2 cm, the radius of the large circle is 3 times that, the circumference of the small circle is the circumference of the large circle
小圆的半径2厘米，大圆的半径是它的3倍，小圆的周长是大圆周长的多少
<gadget id="calculator">2 * 3.14 * 2</gadget>
<output>12.56</output>

<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">2 * 3.14 * 6</gadget>
<output>37.68</output>

<gadget id="calculator">12.56 / 37.68</gadget>
<output>0.333333</output>

<result>0.333333</result>