1. Algebraic Expressions and Integers
Pre-Algebra Chapter 1
Algebraic Expressions and Integers

2. Section 1-1 Variables and Expressions
is a letter or a symbol that replaces a number.
Variable
Variable expression
is a mathematical phrase that uses variable, numbers and operation symbols.
Numerical expression
is a mathematical phrase that uses numbers and operation symbols.

3. Examples
Identify each expression as a numerical expression or a variable expression. For a variable expression, name the variable.
7 x 3
8 + m
x + y
27/9 5m k

4. Keywords Addition Subtraction Multiplication Division TOTAL SUM
MORE THAN
INCREASED BY
DIFFERENCE
FEWER THAN
LESS THAN
DECREASED BY
PRODUCT
TIMES
TWICE
QUOTIENT
DIVIDED BY

5. 1-2 The Order of OperationsMD AS
Work inside grouping symbols
Solve all exponents
Multiply & Divide left to right
Add & Subtract left to right
Remember order of operation by the following saying:
Please Excuse My Dear Aunt Sally

6. Examples
Simplify the following numerical expressions using the order of operations.
a (2)
b. 12/3-1(2)+1
c [(5+2)-1]

7. 1-3 Writing and Evaluating Expressions

8. 1-4 Integers and Absolute Value
Numbers that are the same distance from zero on a number line but in opposite directions are called opposites.
Integers are the set of whole numbers and their opposites.
A number’s distance from zero on a number line is called its absolute value.

9. 1-5 Adding Integers
When adding opposites, the sum is zero

10. Rules for Adding Integers
Same Signs:
The sum of two positive integers is positive. The sum of two negative integers is negative.
Different Signs:
To add two integers with signs, find the difference of their absolute values. The sum has the sign of the integer with the greater absolute value.

11. How to remember rules for Adding integers
Same Signs
Add
Different Signs
Subtract