The numerator of a fraction is multiplied by 4, and the denominator divided by 4 is (4/5). What is the original fraction?
一个分数的分子乘4，分母除以4是(4/5)，原来分数是多少．
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(4/5) / 16</gadget>
<output>1/20 = around 0.05</output>

<result>1/20 = around 0.05</result>