Calculation: (1/2)+(1/6)+(1/12)+(1/20)+...+(1/2450).
计算：(1/2)+(1/6)+(1/12)+(1/20)+…+(1/2450)．
<gadget id="calculator">1 / 50</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">1 - (1/50)</gadget>
<output>49/50 = around 0.98</output>

<result>49/50 = around 0.98</result>