The DROUND( ) function performs double-precision rounding on a value.
expression1 is the value to round.
Double-precision rounding uses 2 words to store a number.
If a precision is not specified as the second expression, DROUND() uses whatever precision is set at the time of the calculation. If no PRECISION statement was issued then the default precision of 4 is used.
You must specify the precision (either with the PRECISION statement or with the optional precision parameter) to be greater than or equal to the rounding digit, otherwise the calculation will truncate the value to the whatever precision is 'active' at the time of the calculation.