This document discusses order of operations and evaluating expressions. It defines variables, numerical expressions, and algebraic expressions. It explains that to evaluate an expression means to solve it. When an expression has multiple operations, order of operations must be followed: 1) evaluate inside parentheses, 2) evaluate exponents, 3) do multiplication and division from left to right, and 4) do addition and subtraction from left to right. The document provides examples of evaluating numerical and algebraic expressions and assigns related classwork and homework problems.

1. Section 1.2 Order of Operation

2. Variable A Variable is a symbol, usually a letter, used to represent a number 4 x n a + 7b 5 + r3x – 4 * t t – 2y – 3 + r

3. Numerical Expression Numerical Expression contains numbers and at least one operation. Examples: 3 + 2 17 * 3 20 / 4 14 – 8 21 - 5 + 2 1000 / 8 + 123

4. Algebraic Expression An Algebraic Expression contains variables, numbers and at least one operation symbol. Which of the following is NOT an Algebraic Expression? 4 x n a + 7b 5 + r3x – 4 * t t – 2y – 3 + r

5. Evaluate an Expression To Evaluate an expression means to ‘solve’ the expression. For example: Evaluate the following numerical expressions: 1. 3 + 4 2. 12 / 2 3. 7*6

6. Evaluate the following algebraic expressions, if a=2 b=5 c=8: a + 13 2. 19 – b 3. a * c 1. 2 + 13 2. 19 – 5 3. 2 * 8

7. If an expression has more than one operation you must use: ORDER OF OPERATION

8. ORDER OF OPERATION 1. Evaluate expressions inside grouping symbols. (Parentheses) 2. Evaluate all powers. (Exponents) 3. Do all multiplications and/or divisions from left to right. (Multiplication and Division) 4. Do all additions and/or subtractions from left to right. (Addition and Subtraction) Please Excuse My Dear Aunt Sally

9. Classwork: Page 13 # 4 – 12 EVEN Homework: Page 14 # 24 - 34