Little Ding Ding reads a book. At the beginning, he reads an average of 30 pages a day. After 7 days, he reads half of the book. After 7 days, he reads 5 more pages a day. How many days will it take to finish the book?
小丁丁看一本书，开始时平均每天看30页，7天看了这本书的一半，7天后每天多看5页，还要几天才能看完这本书？
<gadget id="calculator">30 + 5</gadget>
<output>35</output>

<gadget id="calculator">7 / 35</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">30 * (1/5)</gadget>
<output>6</output>

<result>6</result>