Find the law first, then fill in the numbers: (1/1)+(1/2)-1=(1/2), (1/3)+(1/4)-(1/2)=(1/12 ), (1/5)+(1/6)-(1/3)=(1/30), (1/7)+(1/8)-(1/4)=(1/56), ...then (1/2011)+(1/2012)-(how much=(1/(2011*2012)).
先找规律，再填数：(1/1)+(1/2)-1=(1/2)，(1/3)+(1/4)-(1/2)=(1/12)，(1/5)+(1/6)-(1/3)=(1/30)，(1/7)+(1/8)-(1/4)=(1/56)，…则(1/2011)+(1/2012)-(多少=(1/(2011*2012))．
<gadget id="calculator">1 / 2_012</gadget>
<output>1/2_012 = around 0.000497</output>

<gadget id="calculator">(1/2_012) * 2</gadget>
<output>1/1_006 = around 0.000994</output>

<result>1/1_006 = around 0.000994</result>