(1/12)+(1/20)+(1/30)+...+(1/90).
(1/12)+(1/20)+(1/30)+…+(1/90)．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/3) - (1/10)</gadget>
<output>7/30 = around 0.233333</output>

<result>7/30 = around 0.233333</result>