The number A is 20% more than the number B, and the number B is less than the number A
甲数比乙数多20%，乙数就比甲数少多少
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) - 1</gadget>
<output>-4/5 = around -0.8</output>

<gadget id="calculator">1 + (-4/5)</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">(1/5) / (6/5)</gadget>
<output>1/6 = around 0.166667</output>

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