3+3x3-3+3=? use PEMDAS parenthesis exponents multiplication and division across the line left to right addition and subtraction across the line left to right no parenthesis and exponents! do multiplication and division across the line left to right 3 + 9 - 3 + 3 do addition and subtraction across the line 12 - 3 + 3; 9 + 3; 12