I am also getting same issue in the eText output. Just wanted to check in case if you were able to fix it.
This is where i would like to use the format function suggested in note
Oracle XML Publisher Release 12 Known Issues (Doc ID 404928.1)
content from note,
Rounding Issue When Adding Decimal Numbers
As Oracle XDK conforms to XSL standards for IEEE 754, you might encounter rounding issues when adding numbers that are decimals. For example, suppose you add 13683.80 and 516.39, using this syntax in Oracle BI Publisher:
The value returned is 14200.189999999999 which is caused by a limitation based on the IEEE 754 Binary Floating-Point-Arithmetic.
To work around this issue, use the format-number function or the round syntax as shown here to obtain a return value of 14200.19:
<?format-number:(13683.80 + 516.39);'D99'?>
<?(round((13683.80 + 516.39)*100) div 100)?>