Xiaohong has read a total of 108 pages in 9 days. According to this calculation, she can finish the book in 4 more days. How many pages does the book have?
小红9天共看书108页，照这样计算，她再看4天就能把这本书看完，这本书一共多少页？
<gadget id="calculator">108 / 9</gadget>
<output>12</output>

<gadget id="calculator">12 * 4</gadget>
<output>48</output>

<gadget id="calculator">48 + 108</gadget>
<output>156</output>

<result>156</result>