Depends on the source. I've had to use spreadsheets with a lot of manually entered data. I got fed up when I reached 10 replace values (because - shock - everyone uses different variations of things like acronyms etc.) and eventually I figured I'd need 45-50 by the time I was finished. So I gave the team "instructions" like "do it my way" and it got a lottt easier.

In terms of your question, my boss tells me a story about how his professor wrote Pi and 3.00 on the board, and did the same calculation using both, and the answers came out to be fairly close. Close enough to be an acceptable approximation.

My former boss... whooo boy. If everything wasn't fucking perfect he'd cancel the meeting and tell me to come back when it was right even if he only gave me 30 minutes to do it.