to determine or re solve (a question, problem, etc) by calculation or reasoning
I couldn't work out how they kept the prices so low
to devise (something) by resolving difficulties
The parties worked out an agreement
to elaborate (a plan, etc) in detail
to discharge (a debt) by labour
to exhaust (a mine) by working it
to prove effective or successful
The marriage didn't work out
(often + at/to) to amount to (a total or calculated figure)
said of a sum: to yield a result
to engage in physical exercise