In a ratio, the product of two outer terms is the smallest composite number, one inner term is (1/4), and the other inner term is how much.
在一个比例里，两个外项的积是最小的合数，一个内项是(1/4)，另一个内项是多少．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

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

<result>16</result>