The numerator of a fraction is doubled and the denominator is doubled to get (2/7). What is the original fraction?
一个分数的分子扩大2倍，分母缩小2倍后得(2/7)，原分数是多少．
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">7 * 2</gadget>
<output>14</output>

<gadget id="calculator">1 / 14</gadget>
<output>1/14 = around 0.071429</output>

<result>1/14 = around 0.071429</result>