Rounding the values in SAP PI/PO

Hi Experts,

We are facing an issue with rounding the values, please help.

Example:

Incoming values Rounding 90.9091 90.9 90.9091 90.9 90.9091 90.9 90.9091 90.9 90.9091 90.9 90.9091 90.9 90.9091 90.9 90.9091 90.9 90.9091 90.9 90.9091 90.9 90.909 90.9 1000 999.9

After Rounding Sum is not matching....!

In some scenarios if we round for 2 decimals it works and in some it will work with 3 decimals.

Please help me in achieving this in a generic way.

Thanks in advance..!

Regards,

Sateesh.