Teacher Li reads 17 pages of a book every day, and after 105 days, there are still 30 pages left. How many pages does this book have?
一本书，李老师每天看17页，看了105天后还剩下30页．这本书有多少页？
<gadget id="calculator">17 * 105</gadget>
<output>1_785</output>

<gadget id="calculator">1_785 + 30</gadget>
<output>1_815</output>

<result>1_815</result>