Work out the amount (6)
I believe the answer is:
figure
I believe this is a double definition.
'work out' is the first definition.
(I know that work out can be written as figure)
'amount' is the second definition.
(I know that figure is a type of amount)
'the' acts as a link.
(Other definitions for figure that I've seen before include "Build" , "The written symbol of a number" , "Shape; amount of money" , "Imagine; integer" , "Symbol, numeral" .)