I read 78% of a book, how much is left?
一本书看了78%，还剩多少．
<gadget id="calculator">78 / 100</gadget>
<output>39/50 = around 0.78</output>

<gadget id="calculator">1 - (39/50)</gadget>
<output>11/50 = around 0.22</output>

<result>11/50 = around 0.22</result>