Small change (1.50 approximately) son put in box with writing things (6,4)
I believe the answer is:
pencil case
'box with writing things' is the definition.
I can't judge whether this definition defines the answer.
'small change 1 50 approximately son put in' is the wordplay.
'small change' becomes 'pence' (pennies).
'i 50' becomes 'il' (I can't justify this - if you can you should give a lot more credence to this answer).
'approximately' becomes 'ca' (abbreviation for circa).
'son' becomes 's' (genealogical abbreviation for son).
'put in' indicates putting letters inside.
'il'+'ca'+'s'='ilcas'
'pence' enclosing 'ilcas' is 'PENCIL-CASE'.
Can you help me to learn more?
(Other definitions for pencil case that I've seen before include "Clean spice (anag.)" , "drawers here?" , "Crayons may have been put in this" .)