Xiao Ming reads a book and has already read 80 pages, and there are (2/7) left to read. How many pages does this book have?
小明看一本书，已经看了80页，还剩(2/7)没有看，这本书一共有多少页？
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 - (2/7)</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">80 / (5/7)</gadget>
<output>112</output>

<result>112</result>