The ROUND function returns the specified argument, number_operand, rounded to the number of places after the decimal point specified by the integer. If the integer argument is a negative number, it rounds to a place before the decimal point, that is, at the integer part.
ROUND( number_operand, integer )
--it rounds a number to one decimal point when the second argument is omitted
SELECT ROUND(34567.34567), ROUND(-34567.34567);
round(34567.34567, 0) round(-34567.34567, 0)
============================================
34567.00000 -34567.00000
--it rounds a number to three decimal point
SELECT ROUND(34567.34567, 3), ROUND(-34567.34567, 3) FROM db_root;
round(34567.34567, 3) round(-34567.34567, 3)
============================================
34567.34600 -34567.34600
--it rounds a number three digit to the left of the decimal point
SELECT ROUND(34567.34567, -3), ROUND(-34567.34567, -3);
round(34567.34567, -3) round(-34567.34567, -3)
============================================
35000.00000 -35000.00000