Find the difference between 9 (1/18) and 3 (1/18), what is the column formula
求9个(1/18)与3个(1/18)的差，列式是多少
<gadget id="calculator">1 / 18</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">9 * (1/18)</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">(1/2) - (1/6)</gadget>
<output>1/3 = around 0.333333</output>

<result>1/3 = around 0.333333</result>