In grid puzzles, totals often combine a square term} with a product term}. Try decomposing the target into recognizable chunks (e.g., \(a^2+b\times c\)) and solve for the unknown.
Observation: Focusing on the right block that produces \(102\): it is formed from the numbers just below it — \(8\) (to its immediate left in the middle row), and \(6\) and \(4\) in the bottom row — together with the missing value \(x\) in the middle row of that block. Rule (consistent with this block):
\[
102 = 8^2 + (6\times 4) + x
\]
\(⇒\ 102 = 64 + 24 + x \ ⇒\ x=102-88=14.\)
\[
\boxed{x=14}
\]