For a book, I read 168 pages on the first day, the rest (2/3) on the second day, and finished it on the third day, which is exactly (1/7) of the whole book. How many pages does the book have?
一本书，第一天读了168页，第二天读了余下的(2/3)，第三天读完，正好是全书的(1/7)．全书有多少页？
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">(1/7) * 2</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 - (2/7) - (1/7)</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">168 / (4/7)</gadget>
<output>294</output>

<result>294</result>