In a ratio, the two internal terms are reciprocals of each other, one external term is 0.8, and the other external term is 0.8.
在一个比例中，两个内项互为倒数，一个外项是0.8，另一个外项是多少．
<gadget id="calculator">1 / 0.8</gadget>
<output>1.25</output>

<result>1.25</result>