(5/9) plus at least how many times this fractional unit, you get the smallest prime number.
(5/9)至少加上这个分数单位的多少倍，就得到最小的质数．
<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">2 - (5/9)</gadget>
<output>13/9 = around 1.444444</output>

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

<gadget id="calculator">(13/9) / (1/9)</gadget>
<output>13</output>

<result>13</result>