A ratio, the two inner terms are reciprocals of each other, one of the outer terms is 0.45, what is the other outer term.
一个比例，两内项互为倒数，其中一个外项是0.45，则另一个外项是多少．
<gadget id="calculator">1 / 0.45</gadget>
<output>2.222222</output>

<result>2.222222</result>