I read a book but didn’t read it (4/5). I read 80 pages. How many pages are there in this book?
一本书，看了的是没看的(4/5)，看了80页，这本书共多少页？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

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

<gadget id="calculator">100 + 80</gadget>
<output>180</output>

<result>180</result>