ROUND « Numerical Math Functions « Oracle PL/SQL Tutorial

14.17.1.ROUND(x, [y]) gets the result of rounding x an optional y decimal places.
14.17.2.ROUND column value
14.17.3.ROUND for negative value
14.17.4.ROUND may have a second argument to handle precision: means the distance to the right of the decimal point
14.17.5.The second argument of ROUND defaults to 0
14.17.6.The second argument of ROUND, precision, may be negative, which means displacement to the left of the decimal point
14.17.8.ROUND(5.75, 1)
14.17.9.ROUND(5.75, -1) (2)

14.17.10.ROUND(345.678,2) ROUND(345.678,-1) ROUND(345.678,-2)
14.17.11.Demonstrates the ROUND function