Calculate how much 3.9*0.14/(2.1*0.13)=.
计算3.9*0.14/(2.1*0.13)=多少．
<gadget id="calculator">2.1 * 0.13</gadget>
<output>0.273</output>

<gadget id="calculator">0.14 / 0.273</gadget>
<output>0.512821</output>

<gadget id="calculator">3.9 * 0.512821</gadget>
<output>2.000002</output>

<result>2.000002</result>