Obviously read a story book, but read the whole book in the first week (1/5). I read 51 pages in the second week and left 45 pages unread. How many pages are there in this book?
明明看一本故事书，第一周看了全书的(1/5)．第二周看了51页，还剩45页没有看，这本书共有多少页？
<gadget id="calculator">51 + 45</gadget>
<output>96</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">96 / (4/5)</gadget>
<output>120</output>

<result>120</result>