The summer camp starts on July 28th and ends on August 5th. How many days does the summer camp last?
夏令营从7月28日开始，8月5日结束，这次夏令营共多少天．
<gadget id="calculator">31 - 28</gadget>
<output>3</output>

<gadget id="calculator">3 + 1 + 5</gadget>
<output>9</output>

<result>9</result>