In the ratio, the two outer terms are reciprocals of each other, one of the inner terms is 0.25, and the other inner term is what.
在比例中，两个外项互为倒数，其中一个内项是0.25，另一个内项是多少．
<gadget id="calculator">1 / 0.25</gadget>
<output>4</output>

<result>4</result>