When Huahua reads a book, he reads an average of 12 pages a day. After 3 days, there are still 16 pages left. How many pages does this book have?
华华看一本书，平均每天看12页，看了3天后还剩下16页，这本书一共有多少页？
<gadget id="calculator">12 * 3</gadget>
<output>36</output>

<gadget id="calculator">36 + 16</gadget>
<output>52</output>

<result>52</result>