If the numerator of a fraction is enlarged by 3 times and the denominator is reduced by 3 times, the value of the fraction will be enlarged by as many times as possible.
一个分数的分子扩大3倍，分母缩小3倍，分数值就扩大多少倍．
<gadget id="calculator">3 / 1</gadget>
<output>3</output>

<gadget id="calculator">1 * 3</gadget>
<output>3</output>

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

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

<gadget id="calculator">3 / (1/3)</gadget>
<output>9</output>

<result>9</result>