1-(1/(1+2))-(1/(1+2+3))-(1/(1+2+3+4))-…-(1/(1+2+3+ 4+...+100))=how much.
1-(1/(1+2))-(1/(1+2+3))-(1/(1+2+3+4))-…-(1/(1+2+3+4+…+100))=多少．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 101</gadget>
<output>1/101 = around 0.009901</output>

<gadget id="calculator">(1/2) - (1/101)</gadget>
<output>99/202 = around 0.490099</output>

<gadget id="calculator">2 * (99/202)</gadget>
<output>99/101 = around 0.980198</output>

<gadget id="calculator">1 - (99/101)</gadget>
<output>2/101 = around 0.019802</output>

<result>2/101 = around 0.019802</result>