Error in binary arithmetics

megaflop

Hello everyone !
I got a problem, I can't figure out why when I compute [itex]A+B[/itex] and [itex]2\times (\frac{A}{2}+\frac{B}{2})[/itex] the result is sometimes different.
Can anyone explain why the results of the two operations are different ?

Edit : A and B are coded in binary of course and we compute a binary addition.

jim hardy

Are you using integer or floating point ?

My guess is former , and one of the numerators is an odd number.

megaflop

Integers I forgot to mention sorry.

jim hardy

Well there ya go.

Got Basic?

FOR I = 1 , 10 , 1
PRINT I, INT( I/2)
NEXT I
END

megaflop

Quote by jim hardy

Well there ya go.

Got Basic?

FOR I = 1 , 10 , 1
PRINT I, INT( I/2)
NEXT I
END

I see thank you :) .

uart

Quote by megaflop

Integers I forgot to mention sorry.

Does only "misbehave" if you're using one or more odd integers?

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megaflop	Error in binary arithmetics Tweet Hello everyone ! I got a problem, I can't figure out why when I compute [itex]A+B[/itex] and [itex]2\times (\frac{A}{2}+\frac{B}{2})[/itex] the result is sometimes different. Can anyone explain why the results of the two operations are different ? Edit : A and B are coded in binary of course and we compute a binary addition.

jim hardy Recognitions: Gold Member Science Advisor	Are you using integer or floating point ? My guess is former , and one of the numerators is an odd number.

jim hardy Recognitions: Gold Member Science Advisor	Error in binary arithmetics Well there ya go. Got Basic? FOR I = 1 , 10 , 1 PRINT I, INT( I/2) NEXT I END