Honghong reads a 140-page story book, and has already read (4/7) of the total number of pages in the book. How many pages are there yet?
红红看一本140页的故事书，已经看了全书总页数的(4/7)．还有多少页没有看？
<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">1 - (4/7)</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">140 * (3/7)</gadget>
<output>60</output>

<result>60</result>