(1/(2*4))+(1/(4*6))+(1/(6*8))+...+(1/(48*50)).
(1/(2*4))+(1/(4*6))+(1/(6*8))+…+(1/(48*50))．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 50</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">(1/2) - (1/50)</gadget>
<output>12/25 = around 0.48</output>

<gadget id="calculator">(1/2) * (12/25)</gadget>
<output>6/25 = around 0.24</output>

<result>6/25 = around 0.24</result>