Counting system with a point to it (7)
I believe the answer is:
decimal
This clue is a double definition.
'counting system' is the first definition.
(decimal or base-10 is a system of counting)
'with a point to it' is the second definition.
(as in a decimal point)
(Other definitions for decimal that I've seen before include "Relating to ten" , "Medical (anag.)" , "Claimed, wrongly, to have this currency" , "Based on the number 10" , "System based on ten" .)