ASP Round function not behaving as expected

Question

I'm rounding up my decimal values to integer values ex:

I have 5 numbers whose % sum should end up being 100% but i get 101% my values are

11.11111, 80.55555, 5.55555, 2.77777

and on rounding them i get

11, 81, 6, 3 => 101

In above for example 5.555556 rounds up to 6 (correct value) but is screwing up my total for percentage which is going above 100 when i round and add numbers. How can i force or change round function to give desired value? I'm using

round(100 * (x1/sum) )

My output on webpage is like: (i want to display % rounded up to int)

field value %
x      8    11
y      58   81

Is this not possible?

Note: I'm using asp round function - updated

Answer 1

It looks to me like 5.556 should round to 6, actually. Maybe your school taught math differently?

Answer 2

Why do you think 5.55556 should round to 5? Rounding algorithms round up OR down, depending on which integer is closest. Clearly 6 is closer to 5.55556 than 5 is (it's great than 5.5,) so 6 is the expected and correct answer.

Take a look at the floor and ceil functions for alternative implementations of always rounding down and always rounding up respectively.

-Oisin

Answer 3

Maybe you mistyped, but 5.55556 should actually round UP to 6 (anything .5 and above rounds up, and anything below .5 rounds down). If you want better control, then I would look into the floor and ciel functions. floor always rounds down and ciel always rounds up.

Answer 4

try doing:

round(100m * (x1/sum) )

which should force both factors to be treated as decimals instead of ints. Also, make sure (x1/sum) doesn't have a greater number in the denominator.

Answer 5

You should add all your values then do the rounding.

By nature, rounding gives you a little more or a little less. So if you add values that all are a little more you will get over 100.

Answer 6

VB (and VBScript / ASP 3) uses banker's rounding (or "round to the nearest even") so:

1.5 rounds to 2
2.5 rounds to 2
3.5 rounds to 3
4.5 rounds to 4
... etc.

I would suggest doing as Jim Schubert suggested and writing your own rounding function to round properly.

This page has some good info about rounding across all vb-esque languages:

http://support.microsoft.com/kb/196652

Answer 7

If you do individual roundings, and than want the total to be some exact number too, the last individual number must always be the end-result minus all previous rounded numbers.

This is the case in ASP but also the case in Excel f.i. AFAIK this is the only way to achiveve this.