Xiaoli has read 100 pages of a book, and there are (3/5) left unread. How many pages does this book have?
一本书，小丽已经读了100页，还剩(3/5)没有读，这本书共有多少页．
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">100 / (2/5)</gadget>
<output>250</output>

<result>250</result>