Calculate with a simple method: (1/(2*3))+(1/(3*4))+(1/(4*5))+…+(1/(9*10))+(1/ (10*11)).
用简便方法计算：(1/(2*3))+(1/(3*4))+(1/(4*5))+…+(1/(9*10))+(1/(10*11))．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 11</gadget>
<output>1/11 = around 0.090909</output>

<gadget id="calculator">(1/2) - (1/11)</gadget>
<output>9/22 = around 0.409091</output>

<result>9/22 = around 0.409091</result>