The young pioneers of our school participated in the 2008 summer camp. They set off on July 28 and returned on August 5. How many days will the summer camp be held for?
我们学校的少先队员参加2008年夏令营活动，他们7月28日出发，8月5日回来．这次夏令营活动举办多少天．
<gadget id="calculator">31 - 28</gadget>
<output>3</output>

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

<result>9</result>