The most common and most likely answer to this crossword clue is the 10 letter word INNUMERATE
I've seen this crossword clue in Financial Times
I
N
N
U
M
E
R
A
T
E
More clues leading to the result INNUMERATE
Buddy explains!
The straight part
We know that "unable to figure things out" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case unable to figure things out = innumerate.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does INNUMERATE mean?
INNUMERATE noun- One who lacks numeracy skills.
- Lacking numeracy.