How many different ways can a visiting nurse visit 9 patients if she wants to them all in one day?
$$9! = 9 \times 8 \times 7 \times 6 \times 5 \times 4 \times 3 \times 2 \times 1 = 362,880$$
Therefore, there are 362,880 different ways the visiting nurse can visit the 9 patients in one day.