If A is more than B (1/5), how much less is B than A
如果甲比乙多(1/5)，则乙比甲少多少
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">1 * (6/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">(6/5) - 1</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) / (6/5)</gadget>
<output>1/6 = around 0.166667</output>

<result>1/6 = around 0.166667</result>