(1/(1*2))+(1/(2*3))+(1/(3*4))+(1/(4*5))+…+(1/(199*200) ) = how much.
(1/(1*2))+(1/(2*3))+(1/(3*4))+(1/(4*5))+…+(1/(199*200))=多少．
<gadget id="calculator">1 / 200</gadget>
<output>1/200 = around 0.005</output>

<gadget id="calculator">1 - (1/200)</gadget>
<output>199/200 = around 0.995</output>

<result>199/200 = around 0.995</result>