A book has 300 pages in total. Xiaojun has read (7/30) of this book, so how many pages are left?
一本书共有300页，小军看了这本书的(7/30)，那么还剩多少页没看．
<gadget id="calculator">7 / 30</gadget>
<output>7/30 = around 0.233333</output>

<gadget id="calculator">1 - (7/30)</gadget>
<output>23/30 = around 0.766667</output>

<gadget id="calculator">300 * (23/30)</gadget>
<output>230</output>

<result>230</result>