rounding error

[winde]

Hi, i'm facing an issue with rounding error and i would like to know if there is a way to solve it.
below is an simple example.

[TABLE="width: 490"]
<colgroup><col style="text-align: center;"><col style="text-align: center;"><col style="text-align: center;"><col span="3" style="text-align: center;"></colgroup><tbody>[TR]
[TD="align: center"]quantity[/TD]
[TD="align: center"]a[/TD]
[TD="align: center"]b[/TD]
[TD="align: center"]c[/TD]
[TD="align: center"]d[/TD]
[TD="align: center"][/TD]
[/TR]
[TR]
[TD="align: center"]50[/TD]
[TD="align: center"]35%[/TD]
[TD="align: center"]21%[/TD]
[TD="align: center"]16%[/TD]
[TD="align: center"]28%[/TD]
[TD="align: center"][/TD]
[/TR]
[TR]
[TD="align: center"]using int formula[/TD]
[TD="align: center"]17[/TD]
[TD="align: center"]10[/TD]
[TD="align: center"]8[/TD]
[TD="align: center"]14[/TD]
[TD="align: center"]49[/TD]
[/TR]
[TR]
[TD="align: center"]using round formula[/TD]
[TD="align: center"]18[/TD]
[TD="align: center"]11[/TD]
[TD="align: center"]8[/TD]
[TD="align: center"]14[/TD]
[TD="align: center"]50[/TD]
[/TR]
</tbody>[/TABLE]

​

but technically, 18+11+8+14=51

so how can i get exact 50 quantity?

Thanks.

 

[mole999]

Round just does that, up or down by the result, finacial rounding is even more erractic. The results you are getting are what really happens. Just looking at the values 18 is half of 36 and 11 half of 22

 

[steve the fish]

There is no way to solve what you have there. The only way for the numbers to total the 50 is if you dont round them. Rounding can produce totals that differ slightly than the original total. You could format them to look like integers whilst retaining their underlying value. All depends what you are using it for.