Why 4 equals 5?

Question

Please calculate the following formular without any division in it:&nbsp;=int((6.05-6)*100)&nbsp;&nbsp;

detlef_lewin · Answer

Hello Rolf&nbsp;That's the famous Floating Point Error.&nbsp;Tutorial to Understand IEEE Floating-Point Errors&nbsp;How To Implement Custom Rounding Procedures&nbsp;Floating point (Wikipedia)&nbsp;IEEE floating point (Wikipedia)&nbsp;Floating Point Numbers - Computerphile (with Tom Scott)&nbsp;

rolf hansmann · Answer

I thought a dividing operation is required to get an floating point error. This is a minus operation??

detlef_lewin · Answer

Well, you thought incorrectly.The kind of arithmetic operation does not matter.&nbsp;

rolf hansmann · Answer

and what to do about it if it occurs at the 2 place after the decimal point and other programs like Spss or SAS are calculating it right. i might be wrong but for me it seems other programmers where able to avoid it by better implementing the algorithms or using a better library.I calculated this with many programs and you find right and wrong.

detlef_lewin · Answer

In Excel your are more or less limited to this:How to correct rounding errors in floating-point arithmetic&nbsp;

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Why 4 equals 5?

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