measuring with a micrometer and cutting with an axe.
This has been a major problem since we obtained general access to digital computers spitting out answers to a precision of a squillion decimals but still maintaining a reasonably realistic accuracy of real world figures. Aircraft weight and cg is my favourite - I see numbers to a precision of, say, 2 or 3 decimals where the accuracy is still, maybe, a quarter inch or worse (on a good day).
Especially with younger folk, GIGO is a real hazard across the board.