My mother traveled to Hainan Island on July 29 and returned to Changsha on August 7. How many days have passed?
妈妈7月29日去海南岛旅游，8月7日回到长沙，一共经过了多少天．
<gadget id="calculator">3 + 7</gadget>
<output>10</output>

<result>10</result>