(2/(3*4*5))+(2/(4*5*6))+(2/(5*6*7))+(2/(6*7*8))+(2 /(7*8*9))+(2/(8*9*10)).
(2/(3*4*5))+(2/(4*5*6))+(2/(5*6*7))+(2/(6*7*8))+(2/(7*8*9))+(2/(8*9*10))．
<gadget id="calculator">3 * 4 * 5</gadget>
<output>60</output>

<gadget id="calculator">2 / 60</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">4 * 5 * 6</gadget>
<output>120</output>

<gadget id="calculator">2 / 120</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">5 * 6 * 7</gadget>
<output>210</output>

<gadget id="calculator">2 / 210</gadget>
<output>1/105 = around 0.009524</output>

<gadget id="calculator">6 * 7 * 8</gadget>
<output>336</output>

<gadget id="calculator">2 / 336</gadget>
<output>1/168 = around 0.005952</output>

<gadget id="calculator">7 * 8 * 9</gadget>
<output>504</output>

<gadget id="calculator">2 / 504</gadget>
<output>1/252 = around 0.003968</output>

<gadget id="calculator">8 * 9 * 10</gadget>
<output>720</output>

<gadget id="calculator">2 / 720</gadget>
<output>1/360 = around 0.002778</output>

<gadget id="calculator">(1/30) + (1/60) + (1/105) + (1/168) + (1/252) + (1/360)</gadget>
<output>13/180 = around 0.072222</output>

<result>13/180 = around 0.072222</result>