Xiao Ming reads a story book. On the first day, he read the whole book (1/10) with 10 more pages. On the second day, he read the whole book (1/4) with 20 pages less, leaving 270 pages. How many pages are there in total? ?
小明看一本故事书，第一天看了全书的(1/10)多10页，第二天看了全书的(1/4)少20页，还剩下270页，全书一共有多少页？
<gadget id="calculator">270 - 20</gadget>
<output>250</output>

<gadget id="calculator">10 + 250</gadget>
<output>260</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/10) - (1/4)</gadget>
<output>13/20 = around 0.65</output>

<gadget id="calculator">260 / (13/20)</gadget>
<output>400</output>

<result>400</result>