Xiao Ming has read the whole book (2/5) of a story book, and has not read the rest of the book.
一本故事书，小明已看了全书的(2/5)，还剩下全书的多少没有看．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<result>3/5 = around 0.6</result>