This is important. When handling a financial audit, you'll have to redo calculations and formulas to ensure the numbers provided are accurate. You'll have to know the local applicable tax rates and all other variables.
If you find something that doesn't add up you, you'll have to go back to the person who submitted it and let them know so it can be corrected. As the auditor, it's not your responsibility to fix the error, it's your job to report it.
"If I find a math error on some documentation, my first step would be to verify with a colleague that I'm not incorrect. Math can be wrong on either side of the equation. Maybe I have the wrong tax rate. If they concur with me, then I'd take it to the person or point of contact to rerun and correct the numbers. People are human. Errors occur all the time, which is why they have auditors and checks and balances to catch these things."
"If I encountered an error, I'd confer with a co-worker or my boss to determine exactly where they went wrong. Then I'd take it back to the company, client, or person who submitted it and have them correct it. Once it was corrected, I'd continue the audit."
"This happens all the time in companies that don't have a strong check and balance system. You would return the document to the submitter and explain the error. They'd work their way back to fix the error and adjust all documentation affected before resubmitting it to the audit team to continue the audit."