1. PRE-ALGEBRA

2. Lesson 1-2 Warm-Up

3. PRE-ALGEBRA How do you simplify a numerical expression? To simplify a numerical expression, use the order of operations. To remember the order of operation, remember the acronym P.E.M.D.A.S. which stands for “Please Excuse My Dear Aunt Sally” for: 1. Parenthesis (work within grouping symbols inside out: [i.e. ( ), [ ], { } ] 2. Exponent, 3. Multipliaction and Division (from left to right), and 4. Addition and Subtraction (from left to right) Example: The Order of Operations (1-2)

4. PRE-ALGEBRA Example: Simplify 24  [6 – (2 2)]. 24  [6 – (2 2)] Given. 24  [6 – (4) ] Parenthesis (Inside) 24  2 Parenthesis (Outside) 12 Divide Example: Suppose you buy the items shown in the store receipt. Write and simplify an expression to find the total cost of the items with tax. 3 $35 + 4 $15 + $11.96Given. $105 + $60 + $11.96PEMDAS. $165 + $11.96PEMDAS. $176.96PEMDAS     The Order of Operations (1-2)

5. PRE-ALGEBRA Simplify 8 – 2 2. 8 – 2 2 8 – 4 First multiply (PEMDAS). Then subtract (PEMDAS). 4 The Order of Operations LESSON 1-2 Additional Examples

6. PRE-ALGEBRA Simplify 12 ÷ 3 – 1 2 + 1. 12 ÷ 3 – 1 2 + 1 Add and subtract from left to right. 2 + 1 4 – 2 + 1 Multiply and divide from left to right. 3 Add. The Order of Operations LESSON 1-2 Additional Examples

7. PRE-ALGEBRA Simplify 20 – 3[(5 + 2) – 1]. 20 – 3[(5 + 2) – 1] 20 – 3 [7 – 1] Inside parenthesis Outside parenthesis (brackets) 20 – 3 [6] 20 – 18 Multiply from left to right. Subtract. 2 The Order of Operations LESSON 1-2 Additional Examples

8. PRE-ALGEBRA Simplify each expression. 1.7(3) – 2 4 2.6 ÷ 2 + 1 5 3.10 ÷ (4 + 1)4.3[9 2 ÷ (10 – 4)] 2 138 9 The Order of Operations LESSON 1-2 Lesson Quiz