Objective - To recognize and evaluate variable expressions. What is a variable? A variable represents an unknown value. 1) 3 + ___ = 10 2) 6 + = 9 These are all variables 3) 8 + x = 12 4) 5 + = 8

Variable Expressions Variable expressions may consist of variables, constants, and operations. Example Meaning Operation

Sets of Numbers Naturals - Natural counting numbers { 1, 2, 3… } { 1, 2, 3… } Wholes - Natural counting numbers and zero { 0, 1, 2, 3… } Integers - Positive or negative natural numbers or zero { … -3, -2, -1, 0, 1, 2, 3… } Rationals - Any number which can be written as a fraction

…-3, -2, -1, 0, 1, 2, 3... …-3, -2, -1 Sets of Numbers Rationals - any number which can be written as a fraction. , 7, -0.4 Fractions/Decimals Integers , -0.32, - 2.1 …-3, -2, -1, 0, 1, 2, 3... Negative Integers Wholes …-3, -2, -1 0, 1, 2, 3... Zero Naturals 1, 2, 3...

Make a Venn Diagram that displays the following sets of numbers: Naturals, Wholes, Integers, and Rationals. Rationals -2.65 Integers -3 -19 Wholes Naturals 1, 2, 3...

1) -6 Integer , Rational 2) Rational 3) 14 Natural , Whole , Integer Identify all of the sets to which each number belongs. (Reals, Rationals, Irrationals, Integers, Wholes, Naturals) 1) -6 Integer , Rational 2) Rational 3) 14 Natural , Whole , Integer , Rational 4) Integer , Rational

Order of Operations 1) 6 + 5(8 - 2) Parenthesis 6 + 5(6) 6 + 30 = 36 Exponents 2) 2 + 3 25 2 + 75 = 77 Multiply / Divide 3) 8 4 = 32 Add / Subtract 4) 10 - 3 + 8 7 + 8 = 15

Simplify the following. 1) 3) (4 + 18)2 - 10 8 - 9 + 5 (22)2 - 10 -1 + 5 44 - 10 = 34 4 2) 4) 24 - 2[18 6] 8 + 20 24 - 2[3] 4 24 - 6 = 18 28 = 7 4

Evaluate the expression if a = 2, b = 4, and c = 8 1) ab - c 3) 2 (2)(4) - 8 4 + 3(2) 2 8 - 8 4 + 3(4) 2 4 + 12 2 4 + 6 = 10 2) 3a(c - b) 4) 3(2)(8 - 4) 2(4 + 8) 3(2)(4) 2 2(12) 24 24 = = 12 2 2