A 7-meter-long rope has 0.72 meters remaining around the tree, what is the diameter of the tree in meters?
一根7米长的绳子，绕树一周还余下0.72米，树的直径是多少米？
<gadget id="calculator">7 - 0.72</gadget>
<output>6.28</output>

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

<result>2</result>