After reading a book, after reading (1/4), and then reading 25 pages, it is just halfway through. How many pages in this book are there in total?
看一本书，看了(1/4)后，再看25页就刚好看完一半，这本书一共多少页？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/2) - (1/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">25 / (1/4)</gadget>
<output>100</output>

<result>100</result>