Directions: Find the value that completes the number pattern.

300, ?, 312, 334, 330, 356, 354

The correct answer is 318.

To find the missing number, we can analyze the given number sequence by splitting it into two alternating sub-series (the odd-positioned terms and the even-positioned terms):

Given sequence: 300, ?, 312, 334, 330, 356, 354

1. First Sub-series (1st, 3rd, 5th, and 7th terms):
The numbers at odd positions are 300, 312, 330, and 354.
Let's find the difference between consecutive terms in this sub-series:

$312-300=12$

$330-312=18$

$354-330=24$

Notice that the difference increases by 6 at each step ($12+6=18$ and $18+6=24$).

2. Second Sub-series (2nd, 4th, and 6th terms):
The numbers at even positions are ?, 334, and 356.
The difference between the 6th term and the 4th term is:

$356-334=22$

Following the same pattern where the difference increases by 6 at each step, the difference between the 4th term and the missing 2nd term (?) must be:

$22-6=16$

Therefore, we can calculate the missing 2nd term by subtracting 16 from the 4th term (334):

$?=334-16=318$

Thus, the value that completes the pattern is 318.