1. Expressions and Patterns
Chapter 7
Expressions and Patterns

2. Lesson 2 – Order of Operations
The order of operations is a set of rules to follow when more than one operation is used in an expression.
Please Excuse My Dear Aunt Sally
P – All operations in Parentheses are performed first
E – Solve any exponents
M and D – Multiplication and division at the same time from left to right
A and S – Addition and subtraction at the same time from left to right

3. Lesson 2 – Order of Operations
Example: – (3 x 2) + 4² ÷ 4
Parentheses 20 – 6 + 4² ÷ 4
Exponents 20 – ÷ 4
Multiplication 20 – 6 + 4
Division
Addition = 18
Subtraction

4. Lesson 3 – Numerical Expressions
An expression is a number sentence that does not have an equal sign.
A variable represents a number that is not known.
Examples:
Jan had 5 apples. She bought some more.
5 + a
Divide 10 by 2, then add 7.
(10 ÷ 2) + 7

5. Ordered Pairs
A coordinate plane is a flat surface with an x and y axis.
An ordered pair give you an x and y coordinate to plot a point.
To plot an ordered pair:
Start at the origin (0,0)
Use the first number to count across the x axis.
Use the second number to count up from the x axis (y)
So, to plot the point (2,3), I would start at the bottom left of the grid. Then I would go across 2 and up 3.