One moon cake is eaten (1/6), how much of the moon cake is left.
一只月饼吃掉了(1/6)，剩下的占这个月饼的多少．
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 - (1/6)</gadget>
<output>5/6 = around 0.833333</output>

<result>5/6 = around 0.833333</result>