In a ratio, the two outer terms are reciprocals of each other, one of the inner terms is (8/7), and the other inner term is how much.
在一个比例中，两个外项互为倒数，其中一个内项是(8/7)，另一个内项是多少．
<gadget id="calculator">8 / 7</gadget>
<output>8/7 = around 1.142857</output>

<gadget id="calculator">1 / (8/7)</gadget>
<output>7/8 = around 0.875</output>

<result>7/8 = around 0.875</result>