(2/(2*4))+(2/(4*6))+(2/(6*8))+(2/(8*10)).
(2/(2*4))+(2/(4*6))+(2/(6*8))+(2/(8*10))．
<gadget id="calculator">2 * 4</gadget>
<output>8</output>

<gadget id="calculator">2 / 8</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">4 * 6</gadget>
<output>24</output>

<gadget id="calculator">2 / 24</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">6 * 8</gadget>
<output>48</output>

<gadget id="calculator">2 / 48</gadget>
<output>1/24 = around 0.041667</output>

<gadget id="calculator">8 * 10</gadget>
<output>80</output>

<gadget id="calculator">2 / 80</gadget>
<output>1/40 = around 0.025</output>

<gadget id="calculator">(1/4) + (1/12) + (1/24) + (1/40)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>