Add 10 to the numerator of (5/9), and how much to add to the denominator, so that the value of the fraction will not change.
把(5/9)的分子加上10，分母加上多少，分数值大小才不会变．
<gadget id="calculator">9 * 3</gadget>
<output>27</output>

<gadget id="calculator">27 - 9</gadget>
<output>18</output>

<result>18</result>