What is the quotient of the difference between (5/9) and (1/6) divided by their sum?
(5/9)与(1/6)的差除以它们的和，商是多少？
<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

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

<gadget id="calculator">(5/9) - (1/6)</gadget>
<output>7/18 = around 0.388889</output>

<gadget id="calculator">(5/9) + (1/6)</gadget>
<output>13/18 = around 0.722222</output>

<gadget id="calculator">(7/18) / (13/18)</gadget>
<output>7/13 = around 0.538462</output>

<result>7/13 = around 0.538462</result>