Operator Precedence in SELECT statement

*      /     +     -

• Multiplication and division take priority over addition and subtraction
• Operators of the same priority are evaluated from left to right 
• Parentheses are used to force prioritized evaluation and to clarify statements

Operator Precedence with example

SELECT ename,sal,12*sal+100 

FROM emp;

SELECT ename,sal,12*(sal+100)

FROM emp;

In the above examples parentheses makes a lot of differences in arithmetic calculation.