25% of a number is 4, what is the number?
一个数的25%是4，这个数是多少．
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">4 / (1/4)</gadget>
<output>16</output>

<result>16</result>