Calculation: (1/(1+2))+(1/(1+2+3))+(1/(1+2+3+4))+…+(1/(1+2+3+ 4+L+10)).
计算：(1/(1+2))+(1/(1+2+3))+(1/(1+2+3+4))+…+(1/(1+2+3+4+L+10))．
<gadget id="calculator">2 / 11</gadget>
<output>2/11 = around 0.181818</output>

<gadget id="calculator">1 - (2/11)</gadget>
<output>9/11 = around 0.818182</output>

<result>9/11 = around 0.818182</result>