6 (1/9) is (6/9), plus 1 (1/9) is how much
6个(1/9)是(6/9)，再添上1个(1/9)就是多少
<gadget id="calculator">6 / 9</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">(1/9) * 1</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">(2/3) + (1/9)</gadget>
<output>7/9 = around 0.777778</output>

<result>7/9 = around 0.777778</result>