One moon cake, Xiaohong ate (5/12), mother ate (1/12), and left ((())/(())).
一个月饼，小红吃(5/12)，妈妈吃了(1/12)，还剩下((())/(()))．
<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

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

<gadget id="calculator">1 - (5/12) - (1/12)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>