Xiao Ming has read (3/4) of a book, but has not read the rest of the book.
小明看了一本书的(3/4)，还剩下全书的多少没有看．
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 - (3/4)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>