The document discusses the order of operations for evaluating mathematical expressions. It provides examples of how to use the PEMDAS/GEMDAS method (Parentheses, Exponents, Multiplication, Division, Addition, Subtraction) to properly evaluate expressions and get the correct answer. The homework assignment is to practice using the order of operations to evaluate basic algebra expressions.

1. AIM: How do we properly evaluate expressions using the order of operations ? OBJECTIVE: S.W.B.A.T. use the order of operations to properly evaluate expressions Homework: Basics of Algebra – Day 1: 1 - 18 Also extra credit worksheet available at http://www.schoolrack.com/Ikhaanahoyo September 11, 2007 DO NOW Evaluate 70 - 2(5+3). Evaluate means simplify or “find the answer”

2. Debrief of “Do Now” 70 - 2(5+3) 70 - 2(8) 68(8) 70 - 2(5+3) 70 - 2( 8) 70 – 16 544 incorrect 54 correct Subtraction was done before multiplication Multiplication was done before subtraction The parenthesis here means multiplication !

3. The Order of Operations In math an answer is always right or wrong so we have to have a way of letting people know which operation to do in which order so that everyone gets the same answer. This order is called the Order of Operations G raciously E xcuse M y D ear A unt S ally

4. The Order of Operations Grouping Symbols , Exponents , ( Multiplication/Division ), then ( Add/Subtract ) Grouping Symbols 3 2 Exponents 9 ∙4÷2 = 18 Multiplication/Division from left to right 7 – 4 + 2 = 5 Add/Subtract from left to right [],{}, fraction bar , (),

5. The Order of Operations – Example 1 Evaluate 15 ÷ 5 – 3 ∙ 2 A method that has been very successful for working with order of operations is the GEMDAS table. 3 – 3 ∙ 2 3 – 6 -3

6. 10 ÷ (2 2 + 1) The Order of Operations – Example 2 10 ÷ (4 + 1) When you enter grouping symbols GEMDAS starts all over again so the exponents go first! 10 ÷ 5 2

7. Warning!!! No calculators on next quiz !

8. The Order of Operations – Example 3 Evaluate the expression 5 – 3 + 7 ∙ 2 5 – 3 + 14 2 + 14 Why does subtraction come before addition ? 16

9. The Order of Operations – Groupwork 1, 4, 15