need two arrays to tally qtys for calculating a price

What kind of form do you have? LiveCycle or AcroForm?

Please explain more about your form. What are the values entered into the column fields?

It is an Acroform. The values in the size fields are formatted to be numbers (no decimals places). I created a doc-level script that works. If there's a better way of addressing this issue, I'm open to suggestions.

////////////////
// DoTotalCalcSizesBase()
//
// Function for calc the )total qty of smalls * smprice) as one value
// and )total qty of lrgs * upprice) as a second value. Then it totals
// those two values as the final total for the Row.

function DoTotalCalcSizesBase()
{
var cRowName = event.target.name.split(".").pop();
var cSzFld1 = "Size1." + cRowName;
var cSzFld2 = "Size2." + cRowName;
var cSzFld3 = "Size3." + cRowName;
var cSzFld4 = "Size4." + cRowName;
var cSmPrice = "smPrice." + cRowName;
var cSzFld5 = "Size5." + cRowName;
var cSzFld6 = "Size6." + cRowName;
var cUpPrice = "upPrice." + cRowName;

var qtySm = "";
var qtyUp = "";
var qty1Sm = this.getField(cSzFld1).value;
var qty2Sm = this.getField(cSzFld2).value;
var qty3Sm = this.getField(cSzFld3).value;
var qty4Sm = this.getField(cSzFld4).value;
var qty5Up = this.getField(cSzFld5).value;
var qty6Up = this.getField(cSzFld6).value;
var priceSm = this.getField(cSmPrice).value;
var priceUp = this.getField(cUpPrice).value;

{
qtySm = (qty1Sm * 1) + (qty2Sm * 1) + (qty3Sm * 1) + (qty4Sm * 1);
qtyUp = (qty5Up * 1) + (qty6Up * 1);
}
if((qtySm == "" || qtySm == "0") && (qtyUp == "" || qtyUp == "0"))
event.value = "";
else
event.value = (qtySm * priceSm) + (qtyUp * priceUp);
}

You've got the right idea. The only improvement would be to put it in a loop to make it more compact.
When creating tables that will be used in calculations, field names are everything. You can make the coding much easier or much more difficult just by the names you choose. You haven't done bad at all.