* Santa has 9 reindeer: Dasher, Dancer, Prancer, Vixen, Comet, Cupid, Donner, Blitzen, and Rudolph.
* He wants to arrange them in a line.
The Calculation
* For the first spot in line, Santa has 9 choices (any of his reindeer).
* For the second spot, he has 8 reindeer left, so 8 choices.
* For the third spot, he has 7 choices, and so on.
This means the total number of arrangements is: 9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1
This is called a factorial and is written as 9!
The Answer
9! = 362,880
There are 362,880 different ways Santa can arrange his reindeer in a line.