1. 1-1 Patterns and Expressions
Algebra 2

2. Identifying Patterns
Patterns can be represented using words, diagrams, numbers, or algebraic expressions.
What is the next figure?
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3. Look at the figures from right to left. What is the pattern?
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4. Try this on your own.
Draw the next figure.
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5. Numerical Pattern
What is the next number in the pattern
2, 4, 6, 8, ….
6, 3, 0, -3, ….
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6. Variable- a symbol, usually a letter that represents one or more numbers ex: x or n Numerical Expression- mathematical phrase that contains numbers and operation symbols. ex: 3+5 Algebraic Expressions- mathematical phrase that contains one or more variables ex: 3n+5
What is the only difference between an algebraic and a numerical expression?
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7. Using Tables to help identify patterns
Input
Process Column
Output 1 2 3 4 5 n
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8. Input Process Column Output 1 5 2 9 3 13 4 17 n
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9. Expressing a Pattern with Algebra
How many toothpicks are in the 20th figure?
Figure Number
(Input)
Process Column
Number of Toothpicks (output) 1
1(4) 4 2
2(4) 8 3
3(4) 12 n
What is an expression that describes the number of toothpicks in the nth figure?
You can use a table to look for a pattern that relates the figure number to the number of toothpicks
Algebra 2

10. Patterns on Graphs What is the cost of purchasing 5 DVD’s? 10 DVD’s? 1
The graph shows the cost depending on the number of DVDs that you purchase.
What is the cost of purchasing 5 DVD’s?
10 DVD’s?
Input
(x value)
Process Column
Output
(y-value) 1 16 2 32
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11. Section 1-1 Overview
Patterns- look at the figures or numbers from left to right and identify the pattern.
Variables are used in math to represent an unknown number in equations and inequalities.
Using Input/Output tables can help you find patterns.
Algebra 2