Find the Predecessor: Determining the Number Before 31,000

To determine the number that comes immediately before 31,000, we need to find its predecessor.

Step 1: We start with the number 31,000.

Step 2: To find the predecessor, we subtract 1 from this number:

$31,000 - 1$

$= 30,999$

This calculation tells us that the number that comes before 31,000 is 30,999.

Therefore, the correct solution to the problem is $30,999$.