To solve the puzzle, we need to follow the rule that each block above is the sum of the two adjacent blocks directly below it.

Here is the breakdown of the given numbers:

• On the bottom row: 18, 40, 30, 44
• On the second row: The block between 18 and 40 would be $18 + 40 = 58$, the block between 40 and 30 would be $40 + 30 = 70$, and the block between 30 and 44 would be $30 + 44 = 74$.
• On the third row: The block between 58 and 70 is $58 + 70 = 128$, and the block between 70 and 74 is $70 + 74 = 144$.
• On the fourth row: The block between 128 and 144 is $128 + 144 = 272$.

However, the block in the third row has been provided as 122, so there seems to be an inconsistency in this method. This indicates that there might be a different logic behind the pyramid.

But sticking to the assumption that blocks sum up to form the one above:

• The block directly above 122 and the unknown value (which is denoted by the question mark) is 450.
• Thus, the block with the question mark should satisfy: $122 + \text{?} = 450$ Solving for the question mark, we get: $\text{?} = 450 - 122 = 328$

So, the number that replaces the question mark is 328.

Would you like to explore this further or have any questions?

Here are five related questions:

1. What would be the value of the block between 18 and 40?
2. If the sum of 450 and 328 were used for the topmost block, how would that change the pyramid?
3. What happens if the numbers on the bottom row are changed slightly? Does the logic still hold?
4. How would you construct a similar pyramid if you only knew the top value?
5. What mathematical concepts are involved in understanding pyramid puzzles like this?

Tip: For such pyramid puzzles, always start by verifying the logic of how the blocks relate to one another from bottom to top.