Order Of Operations
1: Do operations in Parentheses and other grouping symbols first. If there
are grouping symbols within other grouping symbols do the innermost one
first.
2: Then
Exponent
3: Then  Multiplication or  Division from left to right.
4: And then  
Addition or Subtraction  from left to right
A popular Acronym to Help you Remember the order of operations
(Parenthesis), Exponents, Multiply and Divide, Add and Subtract)
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( PEMDAS )  Please Excuse My Dear Aunt Sally
Example: Simplify the expression by using the order of operations.
(8 + 4 + 3)÷ 3 − 2    
Do the Parentheses first, then do the division,
then add or subtract from left to right.
Answer   3
Steps:
The order of operations  is a special rule in mathematics that tells
us what operation we must do first.
(15)÷ 3 − 2    
5  − 2  = 3