Final answer:
There are 120 different orders in which the Smith children can be served.
Step-by-step explanation:
To find the number of possible orders in which the five Smith children can be served, we can use the concept of permutations. Since each child can be served one at a time, the total number of possible orders is equal to the factorial of the number of children. In this case, it would be 5! (5 factorial).
5! = 5 x 4 x 3 x 2 x 1 = 120
Therefore, there are 120 different orders in which the Smith children can be served.