1. 1.1 Patterns and Expressions
Look at the figures from left to right. What is the pattern? What would the next figure in the pattern look like?
The pattern shows regular polygons with the number of sides increasing by one.
The last figure shown above has six sides, so the next figure would have seven sides.
The next figure in the pattern is a heptagon.

2. Variables and Expressions
A mathematical quantity is anything that can be measured or counted.
Quantities whose values do not change are called constants.
Quantities whose values change or vary are called variable quantities.

4. Expressing a Pattern with Algebra
How many toothpicks are in the 20th figure? What is an expression that describes the number of toothpicks in the nth figure?
Pattern: Multiply the figure number by 4 to get the number of toothpicks.
So, 20(4) = 80. There are 80 toothpicks in the 20th figure.
Therefore, there are 4n toothpicks in the nth figure.

5. More Practice!!!!!
Homework – Textbook p. 7 – 8 #8 – 24.