(2/(2*3*4))+(2/(3*4*5))+(2/(4*5*6))+…+(2/(8*9*10))= How many.
(2/(2*3*4))+(2/(3*4*5))+(2/(4*5*6))+…+(2/(8*9*10))=多少．
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 90</gadget>
<output>1/90 = around 0.011111</output>

<gadget id="calculator">(1/6) - (1/90)</gadget>
<output>7/45 = around 0.155556</output>

<result>7/45 = around 0.155556</result>