There are a total of 80 books on the two bookshelves. Take 8 books from the first bookshelf and put them in the second bookshelf. The number of books on the two bookshelves is equal. How many books are there in the first bookshelf?
两个书架上共80本书，从第一个书架拿8本书放入第二个书架，两个书架的本数相等，原来第一个书架有多少本书．
<gadget id="calculator">8 * 2</gadget>
<output>16</output>

<gadget id="calculator">80 - 16</gadget>
<output>64</output>

<gadget id="calculator">64 / 2</gadget>
<output>32</output>

<gadget id="calculator">32 + 16</gadget>
<output>48</output>

<result>48</result>