Hi. Please I’m getting this unusual rounding error when summing numbers using the Decimal Library My result is off by 0.01 208,505,442,949.08 # Excel 208,505,442,949.09 # sum function with Decimal Any suggestions please? Thanks. https://gist.github.com/CharlesOkwuagwu/28bfc5707a8c…

Parsing and summing the list as float gives: 208505442949.07806, rounding this to 2 decimal places returns 208505442949.08, so obviously Excel and your verification program do use floats and therefore are inaccurate by design… PS: I’ve heard there are still people using Excel to manage their money… …

Afaik excel does use floats, so maybe it’s excel, which is wrong.

all my values are 2-decimal places The Validator Program (some proprietor java program) also tells me the sum is wrong: MMR100: Total is not equal to sum of all monthly balance for scheme… When i manually adjust the sum to that excel value and feed it to the validator .. it validates

All the numbers in that list are 2-dp, how can you get 208505442949.07806 ???

The magic of floats. Floating Point Math

[image] CharlesO: All the numbers in that list are 2-dp, how can you get 208505442949.07806 ??? This exactly is the reason, why you’d even need a library like Decimal. Because floats are not suited for calculating correctly.

[image] NobbZ: PS: I’ve heard there are still people using Excel to manage their money… Every single finance department i have dealt with keeps parallel records in excel. For some some reason there is an innate distrust of records from IT systems

[image] Floating-point arithmetic may give inaccurate result in Excel - Microsoft 365... Discusses that floating-point arithmetic may give inaccurate results in Excel.

[image] NobbZ: No, I do get 9 Bah. I only looked at the text in the post. Did not notice the “this file has been truncated”…

[image] CharlesO: Every single finance department i have dealt with keeps parallel records in excel. That’s horrifying… They really need to be taught how very very VERY bad that is… If they want to use a Microsoft product then they should use Access instead of Excel, it can do everything Ex…

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Rounding Error with Decimal Sum

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NobbZ December 20, 2019, 1:32pm 6

The magic of floats.