(1/(1*4))+(1/(4*7))+(1/(7*10))+...+(1/(31*34)).
(1/(1*4))+(1/(4*7))+(1/(7*10))+…+(1/(31*34))．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">33 / 34</gadget>
<output>33/34 = around 0.970588</output>

<gadget id="calculator">(1/3) * (33/34)</gadget>
<output>11/34 = around 0.323529</output>

<result>11/34 = around 0.323529</result>