Xiao Ming reads a storybook, reads 30% of the whole book on the first day, reads 40% of the whole book on the second day, and reads 70 pages more on the second day than on the first day. How many pages does this storybook have?
小明看一本故事书，第一天看了全书的30%，第二天看了全书的40%，第二天比第一天多看了70页，这本故事书有多少页？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(2/5) - (3/10)</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">70 / (1/10)</gadget>
<output>700</output>

<result>700</result>