(3/5): Add 5.4 to the former term of 9, how much should the latter term be increased to keep the ratio constant.
(3/5)：9的前项加上5.4，要使比值不变，后项应增加多少．
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(3/5) + 5.4</gadget>
<output>6</output>

<gadget id="calculator">6 / (3/5)</gadget>
<output>10</output>

<gadget id="calculator">9 * 10</gadget>
<output>90</output>

<gadget id="calculator">90 - 9</gadget>
<output>81</output>

<result>81</result>