Calculation: (1+(2/5))*(1-(2/5))*(1+(2/7))*(1-(2/7))*…*(1+(2/5) 2013))*(1-(2/2013)).
计算：(1+(2/5))*(1-(2/5))*(1+(2/7))*(1-(2/7))*…*(1+(2/2013))*(1-(2/2013))．
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">2_012 / 2_013</gadget>
<output>2_012/2_013 = around 0.999503</output>

<gadget id="calculator">(3/5) * (2_012/2_013)</gadget>
<output>2_012/3_355 = around 0.599702</output>

<result>2_012/3_355 = around 0.599702</result>