A story book has 455 pages. Xiao Ming read an average of 25 pages a day in the first 12 days. He plans to finish the rest of the book in 5 days. How many pages should he read on average every day?
一本故事书有455页，小明前12天平均每天看25页，他打算剩下的书5天看完，平均每天他应该看多少页？
<gadget id="calculator">25 * 12</gadget>
<output>300</output>

<gadget id="calculator">455 - 300</gadget>
<output>155</output>

<gadget id="calculator">155 / 5</gadget>
<output>31</output>

<result>31</result>