For dad, the right figure (3)
I believe the answer is:
par
'figure' is the definition.
The answer and definition can be both quantities as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'for dad the right' is the wordplay.
I cannot really see how this works, but
'dad' could be 'pa' (both can mean one's father) and 'pa' is found within the answer.
'right' could be 'r' (common abbreviation) and 'r' is found in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for par that I've seen before include "Average or normal score" , "Average standard" , "Rap to get even" , "average degree" , "Normal number of strokes for a hole at golf" .)