One number doesn't match this factorial series: 2, 6, 24, 120, 720, 1000

To identify which number does not match the factorial series, we must first understand the pattern defined by factorials (n!). A factorial, denoted by an exclamation mark, is the product of all positive integers less than or equal to n.

Step-by-Step Analysis
Evaluate the Factorials:

2! = 2 × 1 = 2

3! = 3 × 2 × 1 = 6

4! = 4 × 3 × 2 × 1 = 24

5! = 5 × 4 × 3 × 2 × 1 = 120

6! = 6 × 5 × 4 × 3 × 2 × 1 = 720

Compare with the Provided Series:
The provided series is: 2, 6, 24, 120, 720, 1000.
Comparing this to our calculated factorials, the first five terms (2, 6, 24, 120, 720) perfectly match the sequence of 2!, 3!, 4!, 5!, and 6!.

Identify the Mismatch:
The final number provided is 1000. However, the next term in the factorial sequence should be 7! = 5040. Therefore, 1000 is the number that does not belong in this series.