Microsoft Excel’s New Math
We tend to trust numbers that spit out of spreadsheets, right? I mean, computers are objective and trustworthy!
Not so much. Excel 2007 has a major bug. If you multiply 850 times 77.1, the answer comes out to be 100,000.
Maybe it’s time to update Pierre Gallois’ famous quote:
“If you put tomfoolery into a computer, nothing comes out of it but tomfoolery. But this tomfoolery, having passed through a very expensive machine, is somehow ennobled and no one dares criticize it.”
- Pierre Gallois
How about …“And even if you put good numbers into Excel, tomfoolery may still come out.”
Even my old slide rule, with its 3-sig limited accuracy, delivers 65,5xx… a much smaller error, and easy enough to resolve to the full number with a couple more steps.
- In the comments Ed posted a very good link below to Joel On Software Explaining the Excel Bug – especially interesting because Joel worked on early versions of Excel.
- and Mark at Good Math, Bad Math, discusses The Excel 65,535=100,000 Bug and floating-point operations as related to display and printing.