Calculation: (1-(1/(2**2)))*(1-(1/(3**2)))*(1-(1/(4**2)))*…*( 1-(1/(2009**2))).
计算：(1-(1/(2**2)))*(1-(1/(3**2)))*(1-(1/(4**2)))*…*(1-(1/(2009**2)))．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">2_010 / 2_009</gadget>
<output>2_010/2_009 = around 1.000498</output>

<gadget id="calculator">(1/2) * (2_010/2_009)</gadget>
<output>1_005/2_009 = around 0.500249</output>

<result>1_005/2_009 = around 0.500249</result>