Find the Numbers Before and After 10999: Sequential Number Challenge

To solve this problem, we'll follow these steps:

• Identify the given number: $10999$.
• Find the predecessor by subtracting 1 from $10999$.
• Find the successor by adding 1 to $10999$.

Now, let's work through each step:
Step 1: The problem provides us with the number $10999$.
Step 2: To find the predecessor, we calculate $10999 - 1 = 10998$.
Step 3: To find the successor, we calculate $10999 + 1 = 11000$.

Therefore, the numbers that complete the sequence are $10998$ and $11000$.