(2-1/2)*(2-2/3)*(2-3/4)*(2-4/5)*...*(2-2003/2004)=how much.
(2-1/2)*(2-2/3)*(2-3/4)*(2-4/5)*…*(2-2003/2004)=多少．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) * 2_005</gadget>
<output>2_005/2 = around 1_002.5</output>

<result>2_005/2 = around 1_002.5</result>