A is more than B (2/7), and B is less than A ((())/(())).
甲比乙多(2/7)，乙比甲少((())/(()))．
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">(2/7) - 1</gadget>
<output>-5/7 = around -0.714286</output>

<gadget id="calculator">1 + (-5/7)</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 + (2/7)</gadget>
<output>9/7 = around 1.285714</output>

<gadget id="calculator">(2/7) / (9/7)</gadget>
<output>2/9 = around 0.222222</output>

<result>2/9 = around 0.222222</result>