A "Andersen's Fairy Tales" has 320 pages, and Xiaohong has read 168 pages, how many pages are left?
一本《安徒生童话》有320页，小红看了168页，还剩多少页没看完？
<gadget id="calculator">320 - 168</gadget>
<output>152</output>

<result>152</result>