Mom read a book, read (5/7), and there are 70 pages left, how many pages are there in this book?
妈妈看了一本书，看了(5/7)，还剩下70页没看，这本书有多少页？
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">1 - (5/7)</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">70 / (2/7)</gadget>
<output>245</output>

<result>245</result>