For a fraction, its numerator is doubled and its denominator is doubled (13/14). What is the original fraction?
一个分数，它的分子缩小2倍，分母扩大2倍后是(13/14)，原来的分数是多少．
<gadget id="calculator">13 * 2</gadget>
<output>26</output>

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

<gadget id="calculator">26 / 7</gadget>
<output>26/7 = around 3.714286</output>

<result>26/7 = around 3.714286</result>