Calculation: (1/2)+(1/6)+(1/12)+(1/20)=how much.
计算：(1/2)+(1/6)+(1/12)+(1/20)=多少．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

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

<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(1/2) + (1/6) + (1/12) + (1/20)</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>