In a ratio, the two outer terms are exactly reciprocals of each other, one of the inner terms is 12.5, and the other inner term is 12.5.
一个比例里，两个外项正好互为倒数，其中一个内项是12.5，另一个内项是多少．
<gadget id="calculator">1 / 1.25</gadget>
<output>0.8</output>

<result>0.8</result>