Working out final account (9)
I believe the answer is:
reckoning
'account' is the definition.
(I know that reckoning is a type of account)
'working out final' is the wordplay.
I cannot quite understand how this works, but
'working' could be 'on' (on can mean working or activated) and 'on' is found in the answer.
The remaining letters 'recking' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for reckoning that I've seen before include "estimating?" , "Counting, calculating" , "Settling of accounts" , "Count" .)