Xiaobing has been reading a 230-page book for 5 days, with an average of 18 pages per day, and the rest will take 7 days to finish, how many pages per day on average?
晓冰看一本230页的书，已经看了5天，平均每天看18页，剩下的要7天看完，平均每天看多少页？
<gadget id="calculator">18 * 5</gadget>
<output>90</output>

<gadget id="calculator">230 - 90</gadget>
<output>140</output>

<gadget id="calculator">140 / 7</gadget>
<output>20</output>

<result>20</result>