Xiao Ming reads a storybook. He reads 30 pages on the first day and 50 pages on the second day. He reads 80% of the book in two days. How many pages does this storybook have?
小明看一本故事书，第一天看了30页，第二天看了50页，两天一共看了这本书的80%，这本故事书共有多少页？
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">80 / (4/5)</gadget>
<output>100</output>

<result>100</result>