There are 80 pages left after reading (2/3) of a book. How many pages does this book have?
一本书已看了(2/3)后还剩80页，这本书一共有多少页？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">80 / (1/3)</gadget>
<output>240</output>

<result>240</result>