Xiaohua is reading an interesting story book, and there are 80 pages left after reading (3/7). How many pages are there in this interesting story book?
小华看一本趣味故事书，已经看了(3/7)后还剩80页，这本趣味故事书共多少页？
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 - (3/7)</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">80 / (4/7)</gadget>
<output>140</output>

<result>140</result>