I need a little help with some Arcade formatting in my attribute rules. I have a valid Arcade expression made to return a number, but I am having some issues with a variable doing a mathematical expression.
The variable InletVolume in the following example is supposed to multiply the variable D by 216, then divide it by 1728 then divide it by 27, but all it will return is 0. I have made sure the If/Else expressions are right, and if I just put it as InletVolume = D it gives the right number, but when I ask it to do any calculation such as D * 10 it just returns a 0. I am guessing that I have the formatting wrong for it, but I have tried everything I can think of with it, adding parenthesis, brackets, etc.
Any help you could provide would be great!

Var StructType = $feature.StructureType
var SubType = $feature.Subtype
var D = $feature.DebrisDepth
var B = $feature.BoxDiamIn
var InletVolume = D * 216 / 1728 / 27
var PrereatVol = (((D *
/ 1728) / 27)
var ManholeVolume = 0
var UntrackedVolume = 0
if (StructType == "SD INLET") {
return InletVolume;
} else if (StructType == "PRE-TREATMENT STRUCTURE") {
return PretreatVol;
} else if (StructType == "SD MANHOLE") {
return ManholeVolume;
} else {
return UntrackedVolume;
}