Calculation: (1/(1*2*3))+(1/(2*3*4))+…+(1/(48*49*50)).
计算：(1/(1*2*3))+(1/(2*3*4))+…+(1/(48*49*50))．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 * 2</gadget>
<output>2</output>

<gadget id="calculator">49 * 50</gadget>
<output>2_450</output>

<gadget id="calculator">1 / 2_450</gadget>
<output>1/2_450 = around 0.000408</output>

<gadget id="calculator">(1/2) - (1/2_450)</gadget>
<output>612/1_225 = around 0.499592</output>

<gadget id="calculator">(1/2) * (612/1_225)</gadget>
<output>306/1_225 = around 0.249796</output>

<result>306/1_225 = around 0.249796</result>