Final answer:
When the President arrives and leaves an installation, they typically receive 21 gun salutes as a sign of respect and honor.
Step-by-step explanation:
In the United States, when the President arrives and leaves an installation, they typically receive 21 gun salutes. This tradition dates back to the early days of the United States and is a way to show respect and honor to the President as the Commander-in-Chief of the military.
Each salute consists of firing artillery cannons or guns in a specific sequence. The number of gun salutes is determined by the rank or status of the person receiving the honor. A 21-gun salute is the highest honor given to heads of state or government officials.