Calculation: ((2009-2007+2005-2003+…+5-3+1)/((1/(1*3))+(1/(3*5))+(1/(5*7) )+...+(1/(99*101)))).
计算：((2009-2007+2005-2003+…+5-3+1)/((1/(1*3))+(1/(3*5))+(1/(5*7))+…+(1/(99*101))))．
<gadget id="calculator">1 / 101</gadget>
<output>1/101 = around 0.009901</output>

<gadget id="calculator">1 - (1/101)</gadget>
<output>100/101 = around 0.990099</output>

<gadget id="calculator">1_005 / (100/101)</gadget>
<output>20_301/20 = around 1_015.05</output>

<gadget id="calculator">(20_301/20) * 2</gadget>
<output>20_301/10 = around 2_030.1</output>

<result>20_301/10 = around 2_030.1</result>