(1/2): how much = (1/3): (1/9).
(1/2)：多少=(1/3)：(1/9)．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">(1/2) * (1/9)</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/18) / (1/3)</gadget>
<output>1/6 = around 0.166667</output>

<result>1/6 = around 0.166667</result>