Calculation: (1/(1*2))+(1/(2*3))+(1/(3*4))+(1/(4*5))+…+(1/(998* 999))+(1/(999*1000)).
计算：(1/(1*2))+(1/(2*3))+(1/(3*4))+(1/(4*5))+…+(1/(998*999))+(1/(999*1000))．
<gadget id="calculator">1 / 1_000</gadget>
<output>1/1_000 = around 0.001</output>

<gadget id="calculator">1 - (1/1_000)</gadget>
<output>999/1_000 = around 0.999</output>

<result>999/1_000 = around 0.999</result>