He Cong read a storybook, originally planned to read 45 pages a day, and he could finish it in 6 days. I actually only read 30 pages a day, how many days can I finish it? (Answer with proportional knowledge)
何聪看一本故事书，原计划每天看45页，6天可以看完．实际每天只看30页，几天可以看完？(用比例知识解答)
<gadget id="calculator">45 * 6</gadget>
<output>270</output>

<gadget id="calculator">270 / 30</gadget>
<output>9</output>

<result>9</result>