1. After this lesson, you will be able to:
Identify an arithmetic series
Find the sum of an arithmetic series
Write an arithmetic series as a summation
Identify the difference between a finite and infinite sequence or series.
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You might have to do a little bit of work to find n (the number of terms).
This can be found by subtracting the first and last term then divide by the common difference, then add 1 to count the first term.
You can also use the arithmetic explicit formula to plug in the last term for an & solve for n.

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6. Journal Entry: What IS an arithmetic series?
The sum of a related sequence

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8. Not in the book
Then find the sum.
You will want to find the explicit formula for the sequence first.
Then find the n (Remember: by plugging in the last term for an or subtract the last and first terms and divide by the common difference and then add 1. )

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Then find the sum.

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12. More Examples:
Not in the book
A marching band formation consists of 6 rows. The first row has 9 musicians, the second has 11, the third has 13 and so on. How many musicians are in the last row and how many musicians are there in all?

13. Landing our Big Ideas:
Visualize: I like to visualize the basic ‘chair problem’ to understand the basic structure of what numbers I need and how they are used to find the sum of an arithmetic series.
Arithmetic Series: Know the formulas OR be able to find them.
Summation Notation: Know and understand each piece (lower limit, upper limit, explicit formula).

14. Assignment 7.4:
pg. 523 – 525
# 10 – 14, 17, 18, 20, 22, 25 – 27, 30a, 30b