1+(1/(1+2))+(1/(1+2+3))+...+(1/(1+2+3+...+2011))=how much.
1+(1/(1+2))+(1/(1+2+3))+…+(1/(1+2+3+…+2011))=多少．
<gadget id="calculator">1 / 2_012</gadget>
<output>1/2_012 = around 0.000497</output>

<gadget id="calculator">1 - (1/2_012)</gadget>
<output>2_011/2_012 = around 0.999503</output>

<gadget id="calculator">2 * (2_011/2_012)</gadget>
<output>2_011/1_006 = around 1.999006</output>

<result>2_011/1_006 = around 1.999006</result>