Rounding Inventor Parameters

The other day I was looking to round the value of a parameter. I was actually calculating distance from the floor to the top of a flange on a conical tank and the value came with billion digit precision. It's nice to have it but it doesn't look professional when dimensionsing or measuring from it.

Couple of words on rounding parameters and using functions:

Functions

The following are the supported functions as presented in the Autodesk Inventor help page.

Syntax	Returns Unit Type	Expected Unit Type
cos(expr)	unitless	angle
sin(expr)	unitless	angle
tan(expr)	unitless	angle
acos(expr)	angle	unitless
asin(expr)	angle	unitless
atan(expr)	angle	unitless
cosh(expr)	unitless	angle
tanh(expr)	unitless	angle
acosh(expr)	angle	unitless
asinh(expr)	angle	unitless
sqrt(expr)	unit^1/2	any
sign(expr)	unitless	any (Return 0 if negative, 1 if positive.)
exp(expr)	unitless	any (Return exponential power of expression: for example, return 2 for 100, 3 for 1000, and so on.)
floor(expr)	unitless	unitless (Next lowest whole number.)
ceil(expr)	unitless	unitless (Next highest whole number.)
round(expr)	unitless	unitless (Closest whole number.)
abs(expr)	any	any
max(expr1;expr2)	any	any
min(expr1;expr2)	any	any
ln(expr)	unitless	unitless
log(expr)	unitless	unitless
pow(expr1;expr2)	unit^expr2	any and unitless, respectively
random(expr)	unitless	unitless
isolate(expr;unit;unit)	any	any

The last one isolate is used to change from one unit to another and this if usefull if you need to calculate the number of holes (of type unitles ul) by dividing a linear dimension (of unit mm) by another linear dimension (of unit mm). The normal result will be of type mm and you need to convert it to unitless ul like this:

isolate((total_length / hole_dist); mm; ul)

Now I was looking to round the result of an equation to an integer but the result was surprising.

Round 1497.21 = 1500 ?!?

Ceil 1497.21 = 1500 ?!?

Floor 1497.21 = 1490 ?!?

Round 1497.00 = 1500 ?!?

Ceil 1497.00 = 1500 ?!?

Floor 1497.00 = 1490 ?!?

Round 1497.51 = 1500 ?!?

Ceil 1497.51 = 1500 ?!?

Floor 1497.51 = 1490 ?!?

So in order to get a proper rounding you need to multiply it first by a multiple of 10, then do the operation and divide again by the same 10 multiple.

Round (1497.21 * 10) /10 = 1497

Ceil (1497.21 * 10) / 10 = 1498

Floor (1497.21 * 10) / 10 = 1497

Round (1497.00 * 10) /10 = 1497

Ceil (1497.00 * 10) / 10 = 1498

Floor (1497.00 * 10) / 10 = 1497

Round (1497.51 * 10) /10 = 1498

Ceil (1497.51 * 10) / 10 = 1498

Floor (1497.51 * 10) / 10 = 1497

I am missing something and it's got to do with the unit conversion for sure, but for now this will do.

Hope it helps you as well.

EDIT 16-02-2016:
There is an update for this so come check it out here.

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