book has 500 pages in total. Xiao Ming read it for 4 days, 50 pages a day. It takes 5 days to read the rest, how many pages do I need to read every day?
一本书共500页，小明看了4天，每天看50页．剩下的要5天看完，每天要看多少页？
<gadget id="calculator">50 * 4</gadget>
<output>200</output>

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

<gadget id="calculator">300 / 5</gadget>
<output>60</output>

<result>60</result>