Definition: a*b=(a+b)/(a*b), such as 2*5=(2+5)/(2*5)=0.7, then 0.2*2.5=what
定义：a*b=(a+b)/(a*b)，如2*5=(2+5)/(2*5)=0.7，那么0.2*2.5=多少
<gadget id="calculator">0.2 + 2.5</gadget>
<output>2.7</output>

<gadget id="calculator">0.2 * 2.5</gadget>
<output>0.5</output>

<gadget id="calculator">2.7 / 0.5</gadget>
<output>5.4</output>

<result>5.4</result>