A number make money and gain experience (5)
I believe the answer is:
'gain experience' is the definition.
The definition and answer can be both related to thinking as well as being verbs in their base form.
Perhaps they are linked in a way I don't understand?
'a number make money' is the wordplay.
'a number' becomes 'l' (fifty in Roman numerals).
'make money' becomes 'earn' (I've seen this in another clue).
'and' is the link.
Can you help me to learn more?
(Other definitions for learn that I've seen before include "Succeed in school" , "Renal (anag)" , "Study (at school?)" , "Come to know" , "Be educated" .)