(11/18) minus the sum of (1/6) and (4/9), what is the difference?
(11/18)减去(1/6)与(4/9)的和，差是多少？
<gadget id="calculator">11 / 18</gadget>
<output>11/18 = around 0.611111</output>

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

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">(1/6) + (4/9)</gadget>
<output>11/18 = around 0.611111</output>

<gadget id="calculator">(11/18) - (11/18)</gadget>
<output>0</output>

<result>0</result>