certain library has a period of 10 days for borrowing books. After 10 days, the number of days exceeded will be charged as a delayed service fee of 0.5 yuan per book per day. Congcong borrowed a storybook and planned to read 5 pages a day, and he could read all of them in 18 days. If he wanted to return it on time without paying the late service fee, how many pages should he read at least every day? (Solve with ratio)
某图书室借图书的期限为10天，10天后超过的天数，要按每天每册0.5元收取延时服务费．聪聪借了一本故事书，计划每天看5页，18天可以全部看完，如果他想要准时归还而不交延时服务费，他每天至少要看多少页？(用比例解)
<gadget id="calculator">5 * 18</gadget>
<output>90</output>

<gadget id="calculator">90 / 10</gadget>
<output>9</output>

<result>9</result>