2ExpressionAny combination of numbers and operations (parentheses, exponents, multiply/divide, and addition/subtraction)Examples: 2+23x6-8+4(2+4)x8
3Evaluating an Expression To evaluate an expression- find the numerical value of an expression using order of operations1. Parentheses2. Exponents3. Multiply/Divide4. Add/Subtract
4PEMDASParentheses- Do all problems in parentheses before like problems not in parentheses. If there are more than one set of parentheses do the inner most expression in parentheses and work your way out.Example: 45-2x(15-3) Work the parentheses 1st,15-3 is 12=45-2x12 Now follow order of operationsfrom left to right= Subtract=21 The answer is 21!!
5PEMDASExponents- After working the parentheses you will work the exponents in a problemExample: 4+(8-6)+22 Work Parentheses 1st= Now workExponents= Follow PEMDAS=10 The answer is 10!
6PEMDASMultiply/Divide- perform the multiplication and division from left to right, whatever comes first.Example: 42/7(4-3) Parentheses 1st=42/7(1) Order of Operations from leftto right: Division Next=6(1) Multiply=6 The Answer is 6!
7PEMDASAddition/Subtraction- perform the addition and subtraction of the expression from left to right, whatever comes firstExample: 7(5+(13-4)/3)) Parentheses 1st=7(5+(9)/3)) Division in theparentheses next=7(5+3) Parentheses next=7(8) Multiply=56 The Answer is 56!
8PEMDAS ProofThis is how you are expected to solve your problems. On the left side of the line you work your problem and on the right side of the line you put your justification.Example:Problem: 2+10(8-6)/22Proof:=2+10(2)/22Parenthesis (Subtraction)=2+10(2)/4Exponents=2+20/4Multiplication=2+5Division=7Addition