(1/2)*(1/3)+(1/3)*(1/4)+(1/4)*(1/5)+...+(1/99)*(1/100).
(1/2)*(1/3)+(1/3)*(1/4)+(1/4)*(1/5)+…+(1/99)*(1/100)．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 100</gadget>
<output>1/100 = around 0.01</output>

<gadget id="calculator">(1/2) - (1/100)</gadget>
<output>49/100 = around 0.49</output>

<result>49/100 = around 0.49</result>