Xiao Ming reads a book and reads (1/3) of the whole book on the first day. If he reads another 40 pages, the ratio of what he has read to the rest is 5:4. How many pages does this book have?
小明看一本书，第一天看了全书的(1/3)，如果再看40页，那么已经看的与剩下的比是5：4．这本书有多少页？
<gadget id="calculator">5 + 4</gadget>
<output>9</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(5/9) - (1/3)</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">40 / (2/9)</gadget>
<output>180</output>

<result>180</result>