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

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

3. 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

4. …-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...

5. 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...

6. 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

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

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

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