Work out one divided by five (5)
I believe the answer is:
solve
'work out' is the definition.
(I know that work out can be written as solve)
'one divided by five' is the wordplay.
'one' becomes 'sole' (synonyms).
'divided by' is an insertion indicator (inserted letters divide the word).
'five' becomes 'V' (Roman numeral).
'sole' going around 'v' is 'SOLVE'.
(Other definitions for solve that I've seen before include "Find the answer to a puzzle" , "Find the 3dn to a mystery" , "do crosswords" , "Get the answers" , "Explain (a mystery)" .)