Calculation: (1/6)+(1/12)+(1/20)+(1/30)+...+(1/(2005*2006)).
计算：(1/6)+(1/12)+(1/20)+(1/30)+…+(1/(2005*2006))．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 2_006</gadget>
<output>1/2_006 = around 0.000499</output>

<gadget id="calculator">(1/2) - (1/2_006)</gadget>
<output>501/1_003 = around 0.499501</output>

<result>501/1_003 = around 0.499501</result>