Calculation: (1/2)+(1/6)+(1/12)+(1/20)+...+(1/380).
计算：(1/2)+(1/6)+(1/12)+(1/20)+…+(1/380)．
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 - (1/20)</gadget>
<output>19/20 = around 0.95</output>

<result>19/20 = around 0.95</result>