Dissemble in dramas written about Petty Officer with a mathematical problem (4,6)
I believe the answer is:
play possum
'dissemble' is the definition.
(I know that play possum is a kind of dissemble)
'dramas written about petty officer with a mathematical problem' is the wordplay.
'dramas' becomes 'plays' (I've seen this before).
'written about' indicates putting letters inside.
'petty officer' becomes 'po' (naval abbreviation).
'with' is a charade indicator (letters next to each other).
'a mathematical problem' becomes 'sum' (I've seen this before).
'plays' going around 'po' is 'playpos'.
'playpos'+'sum'='PLAY POSSUM'
'in' is the link.
(Other definitions for play possum that I've seen before include "Feign death" , "Fake death or sleep" , "Feign unawareness" , "Feign sleep/death" , "Feign ignorance" .)