(1/(1*3))+(1/(3*5))+(1/(5*7))+(1/(7*9))+…+(1/(2015*2017) ) = how much.
(1/(1*3))+(1/(3*5))+(1/(5*7))+(1/(7*9))+…+(1/(2015*2017))=多少．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 2_017</gadget>
<output>1/2_017 = around 0.000496</output>

<gadget id="calculator">1 - (1/2_017)</gadget>
<output>2_016/2_017 = around 0.999504</output>

<gadget id="calculator">(1/2) * (2_016/2_017)</gadget>
<output>1_008/2_017 = around 0.499752</output>

<result>1_008/2_017 = around 0.499752</result>