expression + expression   Addition. If either expression is the NULL value, the result is NULL.

expression - expression   Subtraction. If either expression is the NULL value, the result is NULL.

-expression   Negation. If the expression is the NULL value, the result is NULL.

expression * expression   Multiplication. If either expression is NULL, the result is NULL.

expression / expression   Division. If either expression is NULL or if the second expression is 0, the result is NULL.

expression % expression   Modulo finds the integer remainder after a division involving two whole numbers. For example, 21 % 11 = 10 because 21 divided by 11 equals 1 with a remainder of 10.

 Standards and compatibility