In a book, Xiao Ming has read 200 pages, and 60% of the book remains unread. How many pages are left unread?
一本书，小明读了200页，还剩下全书的60%未读，还剩多少页没读？
<gadget id="calculator">60 / 100</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">200 / (2/5)</gadget>
<output>500</output>

<gadget id="calculator">500 - 200</gadget>
<output>300</output>

<result>300</result>