1-(2/(1*(1+2)))-(3/((1+2)*(1+2+3)))-…-(10/((1+2+…+9 )*(1+2+...+10)))=how much.
1-(2/(1*(1+2)))-(3/((1+2)*(1+2+3)))-…-(10/((1+2+…+9)*(1+2+…+10)))=多少．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">10 * 11</gadget>
<output>110</output>

<gadget id="calculator">1 / 110</gadget>
<output>1/110 = around 0.009091</output>

<gadget id="calculator">(1/2) - (1/110)</gadget>
<output>27/55 = around 0.490909</output>

<gadget id="calculator">2 * (27/55)</gadget>
<output>54/55 = around 0.981818</output>

<gadget id="calculator">1 - (54/55)</gadget>
<output>1/55 = around 0.018182</output>

<result>1/55 = around 0.018182</result>