Xiao Liu reads a book. He reads 350 pages on the first day and 340 pages on the second day. He reads exactly 20% of the whole book in two days. How many pages does this book have?
小刘读一本书，第一天读350页，第二天读340页，两天恰好读了全书的20%，这本书有多少页？
<gadget id="calculator">350 + 340</gadget>
<output>690</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">690 / (1/5)</gadget>
<output>3_450</output>

<result>3_450</result>