Calculation: (1/2)+(1/(2+4))+(1/(2+4+6))+(1/(2+4+6+8))+…+(1/( 2+4+6+...+20)).
计算：(1/2)+(1/(2+4))+(1/(2+4+6))+(1/(2+4+6+8))+…+(1/(2+4+6+…+20))．
<gadget id="calculator">1 / 11</gadget>
<output>1/11 = around 0.090909</output>

<gadget id="calculator">1 - (1/11)</gadget>
<output>10/11 = around 0.909091</output>

<result>10/11 = around 0.909091</result>