Heath left after miners, indicating figures (9)
I believe the answer is:
numerical
'indicating figures' is the definition.
'heath left after miners' is the wordplay.
'heath' becomes 'erica' (erica is a kind of heath).
'left' becomes 'l' (common abbreviation).
'after' is a charade indicator (letters next to each other).
'miners' becomes 'num'.
'erica'+'l'='erical'
'erical' after 'num' is 'NUMERICAL'.
(Other definitions for numerical that I've seen before include "of digits" , "Muriel can (anag)" , "Using arithmetic values" , "like characters, perhaps" , "Relating to quantity" .)