Xiao Ming originally had 40 books, and Xiao Ying originally had 30 books. How many books did Xiaoming give to Xiaoying, and they both had the same amount?
小明原有40本书，小英原有30本书．小明给小英多少本书后，两人同样多？
<gadget id="calculator">40 + 30</gadget>
<output>70</output>

<gadget id="calculator">70 / 2</gadget>
<output>35</output>

<gadget id="calculator">40 - 35</gadget>
<output>5</output>

<result>5</result>